Abstract: The explicit expression of Wilson-θ numerical algorithm for multi-dofs(degree of freedoms) dynamic equation is derived， as well as an explicit Wilson-θ dynamic load identification algorithm is proposed， avoiding the iteration error while keeping the characteristics of the implicit iteration algorithm. The algorithm is unconditionally stable when applying appropriate θ value. The recognition effect of the algorithm is verified by an example and an experiment of a cantilever beam， and the results were compared with those from the traditional state space method. The results show that the algorithm not only can accurately identify the rectangular load， the harmonic load and the random load， but also has higher recognition accuracy than state space method.

Key words: Wilson-θ, explicit formular, load identification, unconditionally stable, state-space method