Due to their excellent electrical, optical, mechanical and other physical and chemical properties, two-dimensional transition metal chalcogenide compounds have important application prospects in the fields of electronics and optoelectronics. The MoSe2 material was successfully prepared by the hydrothermal method. The prepared MoSe2 was characterized by SEM and TEM, and the prepared MoSe2 was flower-shaped microspheres with a particle size of about 200-300 nm. The MoSe2 photodetector was prepared by the vacuum filtration method with flexible organic nylon membrane as the substrate, and its photoelectric characteristics were tested under different laser wavelengths and different laser powers. The results showed that the highest responsivity at 520 nm was 7.5×10 -5A/W; when the laser power is 0.5mW, the maximum light detection rate is 1×107 cm·Hz1/2/W; the light responsivity and light detection rate increase with the increase of laser power, and the response time is faster. The rising response time is 4.6 ms, and the falling response time is 1.3 ms.