The invention relates to a bridge type four-colour film flexible printing machine, comprising an upright column shaped like a Chinese character 'men', wherein the upright column is composed of a left upright, a cross beam and a right upright, the left upright is provided with a control device and an unwinding roller, the cross beam is provided with a drying device, the right upright column is sequentially provided with a first colour printing device, a second colour printing device, a third colour printing device and a fourth colour printing device as well as a winding device, the two sides of the right upright column are both provided with pipelines, the drying device is respectively communicated with the first colour printing device, the second colour printing device, the third colour printing device and the fourth colour printing device, and the unwinding roller is connected with a correcting device. The bridge type four-colour film flexible printing machine provided by the invention can timely monitor and adjust longitudinal shift of the film by virtue of the correcting device during unwinding; meanwhile, the automatic winding device is adopted, and material receiving and loading can be realized without stopping a printing machine, thus working efficiency of the printing machine is improved.