The invention discloses a non-contact photoacoustic detecting method based on optical interferometry. The method comprises the following steps of S1, photoacoustic stimulation, S2, optical coherent detection, S3, balance adjustment and S4 detecting window locking. The invention further discloses a non-contact photoacoustic detecting device based on optical interferometry and used for achieving the method. According to the method, the problem that acoustic coupling media must be used in current photoacoustic imaging is solved, and the application range of photoacoustic imaging is widened. High sensitivity is achieved, light spots of probe light can be focused to the micrometer or submicron scale, and high lateral resolution is achieved. Optical detection is adopted, high-speed scanning is easy, and therefore imaging speed can be increased. Real-time detection is carried out to interfere with system sensitivity, balance adjustment is carried out on probe light intensity, and photoacoustic detection is carried out in the state of the highest system sensitivity. The non-contact photoacoustic detecting device based on optical interferometry is further provided, and the stability and repeatability of imaging can be effectively improved.