The invention relates to a photoacoustic microimaging adaptive scanning system and method. The photoacoustic microimaging adaptive scanning system comprises a master control set, a laser, an ultrasonic probe, an infrared ranging device and a drive unit; the infrared ranging device detects first vertical distance between the ultrasonic probe and a first position point of to-be-detected tissue; the infrared ranging device detects second vertical distance between the ultrasonic probe and a second position point of the to-be-detected tissue; the master control set controls the drive unit to drive the ultrasonic probe to move to the position above the second position point according to the first vertical distance and the second vertical distance, and the distance between the ultrasonic probe and the second position point is enabled to be equal to the first vertical distance; the ultrasonic probe collects photoacoustic signals generated from the first position point and the second position point. By the arrangement, the distance between the ultrasonic probe and the to-be-detected tissue can be automatically adjusted when materials or biological tissue lower in flatness are subjected to imaging, real-time focusing is guaranteed, and high-resolution imaging of photoacoustic images is realized.