The invention discloses an installation type double-axis automatic tightening device, which comprises a drive bracket, a front support base, a rear support base, a switch bracket, a servo motor, a reducer, a gear unit, a tightening shaft, a cylinder and a fixing base, and the front end of the drive bracket It is connected with the front support base by bolts, and the end of the drive bracket is connected with the rear support base by bolts. The switch bracket is located in front of the front support base, and is located under the two tightening shafts as a whole. The tightening shaft includes support shafts, shaft end flanges, sleeves, rectangular Keys, bearings, fastening nuts, straight joints, adapters, pistons, disc springs, springs, compression sleeves, tightening sleeves and drive shafts, the support shaft is connected to the driven gear through the key, and the servo motor drives the drive gear to rotate through the reducer . The invention provides an installed double-shaft automatic tightening device suitable for small space and small distance between two shafts.