The invention discloses a piezoelectric energy recovery device integrated with an adaptive mechanical switch. The device comprises a support base, clamps, a piezoelectric cantilever beam energy collector, an amplitude detection mechanism, a system interface circuit and an energy management unit, wherein the energy collector comprises a piezoelectric element, a cantilever beam and first masses; the amplitude detection mechanism comprises switch cantilever beams, light springs and second masses; the system interface circuit is connected with the piezoelectric element and the energy management unit through wires and connected with the first masses and contact points of the light springs through wires. SSHI (synchronized switch harvesting on inductor) technology is adopted, and defects that original electronic switches need to be controlled by additional electronic components and consume electric energy and mechanical switches cannot adapt to amplitude variation and automatically close atpositive and negative extremums of the amplitude are overcome; the device is simple and reliable in structure and has wide application prospect; energy recovery efficiency and average power of outputelectric energy are both higher than those of a common synchronous switch switching energy recovery device.