TC-2 compound flocculant in possession of intensive breakage of emulsification and highly efficient flocculant is chosen and developed through experiments. It aims at the serious emulsification of heavy oil effluent, little density difference between water and oil and slow separate settling. The field application proves that TC-2 compound flocculant is an excellent clarif icant for effluent. It also has good technological adaptability and low cost. Furthermore, it can meet the need of heavy oil effluent treatment and meet the quality standards of oilfield injected water.