摘要： Photomechanical molecular crystals are receiving great attention due to their efficient conversion of light into mechanical work and surpassing advantages including faster response time, higher Young’s modulus and ordered structure various measured photomechanical crystals with different motions (contraction, expansion, bending, fragmentation, hopping, curling and twisting) are springing up in the forefront of smart materials research. The photomechanical motions of these single crystals during irradiation is triggered by solid-state photochemical reactions and accompanied with phase transformation. This short review intends to summarize recent developments in the growing research on photoresponsive molecular crystals. The basic mechanisms of different kinds of photomechanical materials are described in detail, the recent advances of photomechanical crystals for promising applications as smart materials are also highlighted.