The invention belongs to the field of medical instruments, in particular to a medical feedback columnar piezoelectric auto-micro injector, which comprises a piezoelectric ceramic, a silver electrode, an upper cover, an inlet valve block, a lower cover, a pressing buckle, an outlet valve block, a resistance strain gauge, an upper shell, a sealing ring, a lower shell, a lead socket and the like, wherein the upper and the lower covers are adhered at the two ends of a cylinder respectively; the outlet and the inlet valve blocks are fixedly linked on an upper end cover and a lower end cover by the pressing buckle and are finally adhered in the upper and the lower shells. When a piezoelectric pump works and a piezoelectric column is expanded, a negative pressure zone is formed in the cylinder, and the liquid props up the inlet valve block to enter into the column; and meanwhile, the valve block at the outlet is firmly absorbed at the outlet to prevent the liquid from flowing out. When the piezoelectric column is shrunk and the size of the cylinder is decreased, the liquid props up the valve block at the outlet to flow out, a resistance strain sensor on the valve block detects the flow, and the valve block at the inlet is firmly pressed at the inlet to prevent the liquid from flowing back. The medical feedback columnar piezoelectric auto-micro injector is compact in structure and formed by the adhesion of medical silica gel so as to be low in cost, huge in number of potential application groups and suitable for mass production.