A grid speed measurement method based on photoelectric technology is designed. In this method

the displacement of the object is decomposed into two perpendicular directions of x and y

and then converted into corresponding pulse electrical signals. An anti-interference speed measurement algorithm is designed by using confidence interval and the correlation between object displacements at different times. The electrical signal is analyzed

and instantaneous speed of the object can be calculated

and is displayed on the upper personal computer（ PC） in real time through wireless transmission technology. The experimental results show that the motion velocity of the object can be measured accurately by selecting the appropriate speed measuring grid when the micro-control unit（ MCU） sampling frequency is fixed.