Laser spectroscopy is a powerful analytical technique based on the interaction process of light and matter (including absorption, reflection, scattering, refraction, interference, etc.), which can provide various useful information (such as composition, concentration, velocity, flux, etc.) by analyzing the detected spectral signal and combing the related physical principles. With the continuous innovation of modern laser light sources and photodetector devices, the laser spectroscopy technique has also been developed rapidly. In terms of the three core components of the laser spectroscopy system (i.e., laser light source, absorption cell, and photodetector) and signal enhancement and noise suppression methods, various advanced laser spectroscopy techniques or detection methods have been developed. Quartz-enhanced photoacoustic spectroscopy and photothermal spectroscopy is a new and rapidly developing laser spectroscopy technique, which utilizes miniaturized quartz tuning forks as detectors with the advantages of small size, high quality factor, and low cost. Quartz-enhanced photoacoustic spectroscopy is a spectroscopic technique that measuring the aco of light and gas in a radiation-free relaxation process, which utilizes the resonance effect and piezoelectric effect of the quartz tuning fork as an acoustic detector. However, the quartz-enhanced photothermal spectroscopy technique is based on the thermoelastic effect using quartz tuning fork as a light detector. To date, quartz-based enhanced photoacoustic and photothermal spectroscopy have been successfully applied to detect many small molecules with narrow absorption spectra and several large molecules with broad, unresolved spectral absorption features. These two techniques have been widely used for developing real-time and compact trace gas sensors with high sensitivity and selectivity.In this paper, a dual-spectroscopy detection technique based on quartz tuning forks is proposed to further improve the sensitivity of the quartz tuning fork based spectroscopic detection technique. To demonstrate this proposed gas detection technique, atmospheric water vapor (H₂O) was used for the analytic target and a dual-spectroscopy gas detection system based on two quartz tuning fork detectors (i.e. (QCTF1 and QCTF2) is developed by combing a near-infrared (NIR) diode laser emitting near 1 392 nm, the laser beam is directly coupled into an optical fiber collimator and allowing pass between the two vibrating arms of the QCTF1 detector, which is used to detect the photoacoustic signal generated from the absorption process of atmospheric water vapor. The laser beam between the two arms of the QCTF1 is then focused on the surface of the side arm of the QCTF2 detector through a CaF₂ lens, which is used to detect the photothermal signal generated in the same environmental conditions. Moreover, the wavelength tuning characteristics of the laser were measured before the experiments, and the dependence of the emission wavelength on the driving voltage of the DFB laser at a temperature of 34 ℃ was obtained to ensure that the laser emission wavelength could effectively cover the absorption line of H₂O near the optical wavelength of 1 391.67 nm. Since other gas molecules in ambient air, such as CH₄, CO, O₂ and CO₂ have not obvious absorption features near 1 391.67 nm, therefore, the spectral interference from other molecules can be effectively avoided. The resonance profile curve and the signal amplitude of the quartz tuning fork detectors are precisely measured as a function of the excitation position, and the optimal modulation frequency and excitation position are also experimentally determined, which is of great significance to improve the detection sensitivity of the proposed dual-spectroscopy detection technique. To further improving the sensitivity, the wavelength modulation technique is combined with the phase-dependent characteristics, and the effective signal enhancement of the wavelength modulated photoacoustic and photothermal spectral signals are realized by using the difference detection principle, which effectively utilizes the laser power compared with the single spectraldetection method used in the traditional detection scheme. The experimental results show that the overall Signal-to-Noise ratio (SNR) of the proposed dual-spectroscopy detection technique is 1.97 and 1.24 times higher than those of photoacoustic and photothermal spectral signal, respectively, which effectively improves the system detection sensitivity. Finally, the relationship between the photoelectric conversion efficiency of the quartz tuning fork and the incident laser power in the dual-spectroscopy detection technique is investigated. The experimental results show that the quartz tuning fork detector has a good linear response to the incident laser power with a regression coefficient R²=0.996, which indicates the sensitivity can further improved by using laser sources with more high output power.