The invention relates to a sustained release composition, and particularly relates to a water indissolvable/micro-dissolvable drug sustained release composition. The indissolvable/micro-dissolvable drug sustained release composition comprises more than two indissolvable/micro-dissolvable drug sustained release microspheres with different release behaviors. Through combining more than two drug sustained release microspheres with different release behaviors, the slow release composition of the indissolvable/micro-dissolvable drug is free from obvious release delay period or short delay release period, and also free from sudden release; the composition has good sustained release performance, and can maintain effective blood concentration within several weeks or above, thus the drug applying frequency is effectively reduced, the composition can facilitate patient's life and work; moreover, the composition is good for improving the drug applying compliance and convenience of the patient.