According to the limit on bending strength of drilling rod, the deflecting ability of continuous deflecting wire-line coring tool assembly is from 0.2° to 0.5°/m. To satisfy the requirement of wire-line coring, eccentric bearing structure was adopted in deflecting assembly design. Theoretical calculation was made on deflecting ability with geometry analysis method and limiting curature method. The results showed that designed deflecting ability was obtained, and the calculation result with beam-column theory was more exact to actual deflecting rate.