A multi-gamma ray photon simultaneous medicine emission-based time-coincidence nuclear medicine imaging system and method. The system comprises: multiple detector probes arranged in a non-parallel mode, a time coincidence module (3), and a computer platform (4). Each detector probe comprises a collimator (1) and a gamma ray photon detector (2) with a time measuring function. Multiple gamma ray photons radiated by detection radionuclides within a short time form multiple gamma ray photon coincidence events. According to calculation in the method, a point having the smallest sum of distances of projection lines determined by the multiple gamma ray photon coincidence events is a disintegration position of radionuclides, and the distribution of radionuclides in a living body can be obtained by accumulating a certain number of multi-gamma ray photon coincidence events. The imaging system and method simplify a reconstruction algorithm, improve the signal to noise ratio of reconstructed images, lower the requirement for the total count of gamma ray photons, and reduce the irradiation risk to patients.