In view of the functional requirements to the data collecting instrument for collecting the signal of ranging arm of shearer〖JP〗 under coal mine, the OMAPL138 was taken as the processing core.In terms of hardware, external devices were selected and circuit schematic was designed according to the functional requirements of the data collecting instrument; in terms of software, the core was cut and transplanted by selection of the appropriate Linux core version, and drives were developed on the basis of the corresponding external hardware, and the data collecting instrument with ARM and DSP was formed by use of Qt software application and control interface.The functions of collecting, displaying, storing, transmitting and analyzing the arm signal of the electric traction shearercan be realized.