A heat treatment procedure for vehicle driving axle shell is disclosed, characterized in that the procedure comprises quenching and backfiring the entire shell of vehicle driving axle; the quenching and backfiring procedures for the vehicle driving axle shell is accomplished by the following steps of: 1) quenching: a) placing half axle assembly of the vehicle driving axle shell after composite welding into a heat treatment furnace, heating to 900 +/-10 DEF C and keeping temperature for 4 hours; (b) taking out the half axle assembly of the vehicle driving axle shell to dispose in a quenching pool for the quenching treatment, the quenching temperature is900 +/-10 DEF C and the quenching medium is NaCl brine of 5-10%, the temperature of the quenching medium is less than or equal to 40 DEG C;discharging water in case that the cooling time is no less than 1 minute; 2) backfire; placing the half axle assembly of the vehicle driving axle into the heat treatment furnace, heating to 580 +/-20DEF C and keeping temperature for 4 hours plus 10 minutes, cooling naturally at room temperature. The invention settles the defect about weak rigidity of punching axle shell after welding and prolongs service life of the entire axle through the quenching for entire axle shell.