An optical proximity correction method, comprising: dissecting an edge of a design pattern (120/220) to form a segment (Seg1/Seg2); setting target points of the segments (Seg1/Seg2), and if the segments (Seg1/Seg2) translate in a direction vertical to the segments (Seg1/Seg2), controlling tangent points (P1/P2) of the segments (Seg1/Seg2) tangent to a simulated pattern (110/210) to coincide with the target points; computing edge position differences of the target points; and correcting the design pattern (120/220) according to the edge position differences.