In this paper,a high precision timing equipment based on infrared beam detectors is presented and the design of a multiple channel photoelectric cell circuit,a PCA circuit,a CPU control master circuit, a data communication circuit and a keyboard and display circuit is given.The practical test result shows that this timing equipment has the advantages of high precision,multiple channel measurement and additional RS232 and USB communication interfaces compared with the traditional manual stopwatch. It not only can meet the- accuracy requirement of mechanics experiment at universities,but also can provide exact data sources for the theory study and application of brachistochrone and free falling.