Based on four-quadrant photodetector, a double axle autotrack machinery equipment is designed with the low-power MSP430 SCM as its core. It enables the sun panel to keep being vertical to sunlight, so the utilization efficiency of solar energy was greatly improved. The equipment consists of the amplifying circuit, filter circuit, integrating circuit, A/D converter and precise stepping system. The linear tracking precision is up to 0.25 μm, and the tracking precision of coverage angle is 0.25 mrad. The research is helpful to the applications of solar energy.