"逐次近似计算法" can be translated into English as "successive approximation calculation method" or simply "successive approximation method" (when the context clearly implies it's about calculation).
"Successive" means happening one after another in a series.
"Approximation" refers to a value or quantity that is nearly but not exactly correct.
"Calculation method" specifies that it's a way or technique for performing calculations.
In many technical and scientific contexts, "successive approximation method" is sufficient and commonly understood.