The invention discloses a preparation method of high-densification multiferroic (1-y)BiFeO[3-y]Bi[1-x]RxFeO3 composite ceramic, and relates to a preparation method of composite ceramic. The problems that high-densification multiferroic (1-y)BiFeO[3-y]Bi[1-x]RxFeO3 composite ceramic prepared through a traditional method is low in densification and large in leakage current are solved. The method comprises the steps that 1, BiFeO3 pure phase powder is prepared; 2, Bi[1-x]RxFeO3 pure phase powder is prepared; 3, (1-y)BiFeO[3-y]Bi[1-x]RxFeO3 composite ceramic powder is prepared; 4, ball mill mixing is conducted; 5, ball mill mixed powder is dried, ground and granulated; 6, cold isostatic pressing treatment is conducted on sieved powder, and dumping is conducted; 7, a (1-y)BiFeO[3-y]Bi[1-x]RxFeO3 composite ceramic block is prepared; 8 the ceramic block obtained in the seventh step is polished with sand paper, ground, granulated and dumped; 9, a dumped ceramic blank obtained in the eighth step is subjected to secondary sintering, and the composite ceramic is obtained. The preparation method of the high-densification multiferroic (1-y)BiFeO[3-y]Bi[1-x]RxFeO3 composite ceramic is used for the field of composite ceramic.