A piecewise linear interpolation solution for obtaining the radial emission coefficient for optically thick, cylindrically symmetric plasma is presented. Two examples are evaluated with the present interpolation and Young's interation. It is shown that the present interpolation is precise and reliable. By using the present interpolation, the generalized Abel equation is separated to a system of linear algebraic equations and the coefficient matrix of the system is an upper triangular matrix, so the present interpolation is very simple to eva luate and easy to master for experimentalists and less computation time is required.