This paper describes the development background and performance requirements for geotechnical drilling data acquisition equipment. The main structure and performance parameters of geotechnical drilling data acquisition equipment are introduced together with the selection of the electrical control system and the important electrical components. The automatic closed-loop control scheme for constant rpm output at the drill bit is described in detail. Field test has verified that the geotechnical drilling data acquisition equipment can output a constant drilling rate, and accurately collect and store four main drilling parameters.