  We study the evolution of holographic subregion complexity under a thermal
quench in this paper. From the subregion CV proposal in the AdS/CFT
correspondence, the subregion complexity in the CFT is holographically captured
by the volume of the codimension-one surface enclosed by the codimension-two
extremal entanglement surface and the boundary subregion. Under a thermal
quench, the dual gravitational configuration is described by a Vaidya-AdS
spacetime. In this case we find that the holographic subregion complexity
always increases at early time, and after reaching a maximum it decreases and
gets to saturation. Moreover we notice that when the size of the strip is large
enough and the quench is fast enough, in $AdS_{d+1}(d\geq3)$ spacetime the
evolution of the complexity is discontinuous and there is a sudden drop due to
the transition of the extremal entanglement surface. We discuss the effects of
the quench speed, the strip size, the black hole mass and the spacetime
dimension on the evolution of the subregion complexity in detail numerically.
