CLIBASIA-04580, which highly expressed in citrus plants, was selected from 166 secreted proteins predicted by Prasad and was investigated to further understand the pathogenesis of Candidatus Liberibacter asiaticus(CLas). The total DNA of citrus leaves identified as infected with citrus Huanglongbing(HLB) was extracted, and the CLIBASIA-04580 gene was obtained by PCR. The PCR product was extracted and connected to the pET-28α vector by double enzyme digestion, and the positive clones were screened by colony PCR and restriction endonuclease double digestion. The recombinant Escherichia coli BL21(DE3) was induced to express the fusion histidine-labeled recombinant protein 04580 by isopropyl thiogalactoside(IPTG)(0.5, 1.0, 1.5, 2.0 mmol/L). The expression level of the recombinant protein was detected by polyacrylamide gel electrophoresis(SDS-PAGE), and then purified by protein purification nickel column. The results showed that the recombinant protein 04580 with histidine label was successfully expressed, and the expression reached the peak when the concentration of IPTG was 1.5 mmol/L. By SDS-PAGE gel analysis, the recombinant protein 04580 was successfully purified compared with the original protein solution which was not purified by nickel column.