The invention relates to a device for splicing of a timber formwork, in particular to a steel angle set, steel channel set for splicing of the timber formwork and a construction method. A plurality ofsteel angles and steel pins are arranged, at least one steel angle is arranged on one timber formwork, each the steel angel comprises a first edge and a second edge which are perpendicular to each other, the first edges are fixed to the timber formwork, and two steel angles are fixed through one steel pin; the steel angle set further comprises steel channels, each the steel channel comprises a first end and a second end which are parallel to each other, the first ends are fixed to the timber formwork, and when splicing, the steel angles and the steel channels are fixedly connected through thesteel pins. Splicing of timber formwork in the middle part is completed through combination fixing of the steel angles and the steel channels, and splicing of timber formwork the internal corner partof the construction surface is completed through combination fixing of the steel angles and the steel channels; battens are replaced by the steel angles and the steel channels, the problem that the flatness of splicing parts is difficult to guarantee is solved, and the problem that the formwork is extremely prone to being destroyed when form stripping, and consequently the turnover rate of the formwork is lowered, and the cost is increased is solved.