A series of soy protein adhesive were obtained by microcrystalline cellulose and urea modified soy protein and the influence of MCC content and urea concentration on the adhesive properties was studied. The hot-pressing process was further optimized. Experimental results showed that soy proteins modified by MCC (MSP) has greater adhesive strength compared to the unmodified soy protein; there is a optimum content of MCC; soy proteins co-modified by MCC and urea has better adhesive properties than MSP; The optimum hot-pressing process is temperature 100 ℃, hot-pressing pressure 2 MPa and hot-pressing time 10 minutes.