The invention relates to a spraying device, in particular to a building template surface spraying device. According to the building formwork surface spraying device, a formwork can be placed, spraying can be conveniently conducted on the formwork, and using is convenient. A building formwork surface spraying device comprises a supporting plate, a spraying device body and a spraying device body, the supporting frames are arranged on the front side and the rear side of the supporting plate; the three spraying tanks are uniformly arranged on the upper side and the lower side of the two supporting frames at intervals, and the number of the spraying tanks is twelve; and the stretching spray pipes are arranged at the tops of the six spraying tanks on the upper portion in a sliding mode. A push rod drives a first connecting rod to move towards the inner side, the first connecting rod drives an ejector rod to move towards the upper side in the process of moving towards the inner side, the ejector rod drives a second connecting rod to move towards the upper side, the second connecting rod drives a friction plate to move towards the upper side, and the friction plate pushes a template to move towards the upper side, so that the template can be assisted to move towards the upper side; and paint can be conveniently smeared on the side face of the formwork.