In this paper, we demonstrate a high-response thermomechanical microcantilever focal plane array (FPA) using a metamaterial absorber (MA) integrated thermomechanical microcantilever as a pixel for terahertz (THz) imaging at 2.52 THz. The response of the FPA was increased by thinning the silicon nitride (SiNx) thickness of the microcantilever leg but keeping the dielectric layer thickness of the MA unchanged to ensure enough absorption. A THz imaging system based on the high-response FPA was established using two parabolic mirrors to replace ordinary high-density polyethylene (HDPE) THz lenses for THz beam collimation and expansion, which can reduce the transmission loss of lens material to THz waves by more than 40%. THz images of hollow metal plate and different polymers as well as a THz video at a frame rate of 30 Hz were captured by the high-response FPA. The thermomechanical sensitivity was measured to 0.35 deg/K, which is increased by 1.34 times compared with the leg unthinned FPA. The noise equivalent power (NEP) was measured to be 18.0 nW/Hz1/2, which is about 44% of the leg unthinned FPA. The horizontal and vertical resolutions were 350 μm and 40 μm respectively.