Abstract: The present disclose discloses a micro-display optical engine including a micro-LED panel, a coolant, a thin lens, a metal frame, a connecting pillar and a projection lens; the micro-LED panel comprises a substrate, a number of pixel light-emitting micro-LED grains, a glass plate, a metal bracket, a sealing frame, a radiator, a filling adhesive and a transparent heat-conducting adhesive. The present disclose also discloses a single-engine, dual-engine and three-engine full-color projector. The present disclose has remarkable features such as relatively simple production, the ability to achieve preliminary productization, excellent thermal stability of heat dissipation, high contrast and color gamut, laying a certain foundation for the actual productization of the new micro-LED micro-display projection technology.