Based on survey and individual interview research methods，this paper profoundly analyzes the present situation of migrant workers’ public cultural services in W city.Then this paper uses the “Third Space” theory to analyze the self- identity of migrant workers.The result shows that migrant workers’ self- identity is unique,which means that migrant workers’ self- identity are neither farmers nor citizens，but the unique identity of migrant workers.Therefore,public cultural service system should be built with a definite object in view.However，due to the deviation of administrative operation，the government was unaware of this uniqueness and deviated the migrant- workers’ public cultural services.Then the migrant- workers’ different cultural needs were neglected，so the public cultural services equalization became an empty talk.In addition，intangible rejection from urban citizens and migrant- workers’ self- closeness made the situation even more severe.Therefore,this paper proposes several suggestions on how to change policies:the main body’s responsibility consciousness of the local government should be specified,service logic should be followed,operation of culture for migrant- worker should be valued and the “Four Type” public cultural services,that’s,type of demand，type of publicity，type of touchable and type of interaction should be created. 