The invention discloses a reflected wave velocity observation system based on photoelectric sensors and acceleration sensors. The system comprises a plurality of geophones arranged in a straight line at regular intervals on an observed position, and a seismic wave exciter arranged on the ground. The geophones are in communication connection with a host computer. Each geophone comprises a photoelectric sensor and an acceleration sensor. The photoelectric sensors and the acceleration sensors simultaneously acquire the vibration signal of a seismic wave generated by the excited seismic wave exciter, convert the vibration signal of the seismic wave into a corresponding electric signal and send the electric signal to the host computer. The host computer, after receiving the two electric signals, acquire corresponding reflected wave information from the two electric signals respectively, acquire corresponding velocity information according to the reflected wave information, fuse the velocity information by using wavelet transform and a Kalman filtering algorithm so as to obtain a group of velocity information.