Abstract: A data sample system based on CAN bus of tractor test bench was introduced in this paper. Some problems of traditional test bench were solved, such as complex in setting wire, low level of reliability, unfit for connection to net. This system consists of five CAN nodes, each of them can finish the correlative test and send the data to main PC. The main PC communicates with the CAN nodes through PC-CAN adapter. Hardware and software design for the CAN nodes and PC-CAN adapter and system debugging were finished in this project.