The utility model discloses a concrete pressure testing machine, the on -line screen storage device comprises a base, be provided with the stand on the base, be provided with the backup pad on the stand, the upper end of backup pad is equipped with drive arrangement, the backup pad lower extreme is equipped with presses the seat, the base upper end is provided with and pushes down the seat, characterized by: it is equipped with recovery unit to push down a lower extreme, recovery unit is including a relative recovery disc and the 2nd recovery disc who sets up peg graft together between a recovery disc and the 2nd recovery disc. Through being divided into recovery unit a recovery disc and the 2nd recovery disc, utilize to set up and insert tongue and slot between a recovery disc and the 2ndrecovery disc, through inserting the cooperation of inserting between tongue and the slot, play the purpose that can fix or dismantle at any time.