A femtosecond laser micromachining experiment was carried out on a quartz sheet to cut and separate devices with complex shapes from a quartz single crystal wafer. The relationship between the ablation aperture square and laser parameters was studied experimentally at high repetition frequencies of 50 kHz, 100 kHz, and 200 kHz. The etching thresholds of pure quartz at the corresponding repetition frequencies were 3.73 J/cm², 3.45 J/cm², and 3.2 J/cm², respectively. The effects of femtosecond laser pulse energy, scanning speed, and other processing parameters on the cutting quality of microgrooves were studied. The laser pulse energy could change the surface morphology of the machined microgroove significantly. In addition, the machining effect was the best when the scanning speed was approximately 3.5 mm/s. Finally, using optimized process parameters, the resonant tuning fork devices with complex shapes were cut out on a 0.45 mm thick quartz wafer, which generally meets the expected quality requirements.