An inhibitor targeting specific complement, the inhibitor targeting specific complement is a protein, the protein has a targeted inhibition function on the complement activation, and the amino acid sequence of the protein comprises CRIg extracellular domain and complement inhibiting domain; the amino acid sequence of the protein is consist of the CRIg extracellular domain and the complement inhibiting domain connected directly, or indirectly through a linker which can connect the two domains. The preparation method of the inhibitor targeting specific complement comprises connecting the protein polypeptides of the CRIg extracellular domain and the complement inhibiting domain by gene engineering technology. The protein can be used to prepare a drug targeting inhibition of complement activation. The inhibitor targeting specific complement, its preparation method and applications provided by the present invention, can be used in the treatment and prevention of human diseases caused by complement activation disorders. It has great potential application value and development prospects.