The laser-induced fluorescence confocal scanning device and method belongs to the biochip detection technology field. The fluorescence collection and usage efficiency of existing devices is low, and meanwhile the focusing control in the scanning process is very difficult. The invention uses the middle hole full reflection mirror to optical divide the incident laser and the induced reflected fluorescence, and when a laser beam passing through the aperture, the energy loss is small, almost all laser energy can be irradiated to the biochip, and when collecting the fluorescence, the fluorescence collection angle is big, not only improving the efficiency of laser incident, but also improving the fluorescence collection efficiency. Using computer control, it can maintain approximately confocal relation between the light source pinhole and the detector pinhole, and only need focus one time before scanning, making the focusing control easy and convenient.