Q-switching is a technology that converts continuous light into pulse light to obtain high pulse energy and peak power. It is widely used in material processing, biomedicine, nonlinear frequency conversion and other fields. Generally, Q-switching can be divided into passive and active mechanisms. The passive Q-switching is achieved by inserting a saturable absorber into the cavity. Its structure is simple, but the repetition frequencies of the output pulses depend only on the pump power. Active Q-switching uses external drive electro-optic and acousto-optic modulator to adjust the Q factor of the laser to achieve pulse output. These types of Q-switching system can flexibly control the change of pulse repetition rate, but it breaks the all-fiber structure and leads to a high cost. More importantly, the modulator needs to be specially designed because of the narrow working bandwidth. However, we are inspired by the graphene all-optical modulator, which can regulate the attenuation of the specific light in graphene by introducing another frequency of light into the graphene, thus regulating the in-cavity Q factor. In addition, graphene acts as a saturable absorber in the laser cavity. Therefore, we have built an active-passive Q-switched fiber laser based on graphene all-optical modulator, which can not only obtain stable narrow pulse, but also flexibly change the repetition frequency without changing the pump power. It has an all-fiber structure and a wide working bandwidth. At the same time, we also studied the effects of different modulation depths of graphene on the pulse repetition rate and pulse width variation range. Here, the graphene-films are made by spin-coating the graphene Polyvinyl Alcohol (PVA) water solution, which are placed between two fiber connectors to form graphene modulators. We measured the modulation depths and saturation strengths of three graphene (A, B, C), of which the modulation depths are 33.5%, 18.1% and 8.7%, corresponding to saturation strengths of 40, 5.4 and 3.5 MW/cm², respectively. Then, we built an active-passive Q-switched fiber laser, which consists of an active modulated light with a wavelength of 1 310 nm and a passive Q-switched Erbium-doped ring cavity fiber laser with a wavelength of 1 560 nm. First, a passive Q-switching pulse with a repetition frequency of 18.7 kHz and a pulse width of 10.3 μs is obtained when the active modulated light is turned off. After that, we turned on the modulation light and set the repetition frequency of the modulation light to 18 kHz, and obtained a output pulse with a repetition frequency of 18 kHz and the pulse width of 6.34 μs. It can be seen that the repetition frequency of the output pulse is controlled by the repetition frequency of the modulated light, and the output pulse width is significantly narrower than the passive Q-switched pulse width. Further study shows that the output pulse width gradually widens with the increase of the modulation repetition frequency, while the pulse energy and peak power decrease, which is attributed to as the modulation frequency increases, the energy stored in the gain fiber per switching cycle reduces and therefore releases longer pulse with lower pulse energy. The experiment also explored the effects of three graphene films with different saturation strengths on the repetition frequency and pulse width variation range of the output pulse at different pumping powers. It shows that when the modulation depth of graphene modulator is larger, the variation range of output pulse repetition rate is larger, the variation range of output pulse width is smaller, and the maximum variation range of repetition rate is 31.6 ~92.6 kHz. The modulator described in this paper is easier to be integrated into optical system than the traditional modulator, and has a broad application prospect in nonlinear frequency conversion, multi-color pump detection spectrum and other fields. At the same time, the research also provides a reference for selecting suitable graphene films in the field of Q-switched lasers.