An automatic solder paste addition apparatus for a solder paste printer, comprising: a drive apparatus; a push rod driven by the drive apparatus to move the push rod up and down; a pressure plate provided at an end of the push rod, the pressure plate moving up and down as the push rod moves up and down; a support plate fixed in relation to movement of the push rod; characterized in that the apparatus further comprises: a movable plate, having a working position and having an inner side and an outer side, wherein the outer side of the movable plate is disposed on the support plate and is configured to slide up and down relative to the support plate, and the pressure plate is disposed on the inner side of the movable plate and is configured to slide up and down relative to the movable plate; a working platform for bearing a solder paste tub, the working platform being fixed to the movable plate, and moving up and down as the movable plate moves up and down, wherein a lower one-way locking mechanism (144, 134) is provided between the movable plate and the support plate, the lower one-way locking mechanism (144, 134) being configured to lock the movable plate when the movable plate is in the working position, so that the movable plate cannot move downward, wherein the lower one-way locking mechanism (144, 134) comprises a blocking protruding edge disposed at a lower end of the support plate; and a blocked protruding edge disposed on the outer side of the movable plate; wherein the blocking protruding edge is located below the blocked protruding edge, and has a part which forms an overlap with the blocked protruding edge; and wherein an upper locking mechanism (142, 122) is provided between the movable plate and the pressure plate, the upper locking mechanism (142, 122) being configured so that the pressure plate can move relative to the movable plate when the movable plate is not moving, and can also move together with the movable plate when the movable plate is moving, wherein the upper locking mechanism (142, 122) comprises a pulling edge disposed on the pressure plate, and a force-bearing protruding edge disposed on the inner side of the movable plate, wherein the pulling edge is located below the force-bearing protruding edge, and has a part which forms an overlap with the force-bearing protruding edge. a drive apparatus; a push rod driven by the drive apparatus to move the push rod up and down; a pressure plate provided at an end of the push rod, the pressure plate moving up and down as the push rod moves up and down; a support plate fixed in relation to movement of the push rod; a movable plate, having a working position and having an inner side and an outer side, wherein the outer side of the movable plate is disposed on the support plate and is configured to slide up and down relative to the support plate, and the pressure plate is disposed on the inner side of the movable plate and is configured to slide up and down relative to the movable plate; a working platform for bearing a solder paste tub, the working platform being fixed to the movable plate, and moving up and down as the movable plate moves up and down, wherein a lower one-way locking mechanism (144, 134) is provided between the movable plate and the support plate, the lower one-way locking mechanism (144, 134) being configured to lock the movable plate when the movable plate is in the working position, so that the movable plate cannot move downward, wherein the lower one-way locking mechanism (144, 134) comprises a blocking protruding edge disposed at a lower end of the support plate; and a blocked protruding edge disposed on the outer side of the movable plate; wherein the blocking protruding edge is located below the blocked protruding edge, and has a part which forms an overlap with the blocked protruding edge; and wherein an upper locking mechanism (142, 122) is provided between the movable plate and the pressure plate, the upper locking mechanism (142, 122) being configured so that the pressure plate can move relative to the movable plate when the movable plate is not moving, and can also move together with the movable plate when the movable plate is moving, wherein the upper locking mechanism (142, 122) comprises a pulling edge disposed on the pressure plate, and a force-bearing protruding edge disposed on the inner side of the movable plate, wherein the pulling edge is located below the force-bearing protruding edge, and has a part which forms an overlap with the force-bearing protruding edge.