In order to realize the nondestructive detection of apple lesions, an apple lesions detection system based on near-infrared steady-state spatial resolution technology was designed. The system used 830nm semiconductor laser as the light source, and FDS1010 photoelectric detector with large sensitive area and sensitive sensitivity coefficient was selected to realize the nondestructive detection of internal lesions in apple. An experimental platform was built to analyze the performance of the detection system, including current stability, temperature stability and light intensity stability. The system stability met the experimental requirements. Choosing Evans Blue solid preparation of different mass fraction of pure absorption solution, the accuracy and sensitivity of detection device were validated, it was found that with the increase of solution concentration, the absorbance showed linear change trends, and in the pure absorption system in the solution it showed stable detection performance, and with different mass fraction also showed a good resolution performance. According to the principle of spatial resolution detection technology, apple lesions replacing experiment was designed, by changing the position of the light source, and recording the distance between the source-agent, on the basis of the diffuse transmission equation of the optical parameters of apple lesion location, it was consistent with the known apple internal tissue optical parameters, the results showed that the system can realize the nondestructive detection of apple internal lesions.