The invention discloses a method for calculating temperature rise of a reactor based on a visualization algorithm. The length l of a magnetic path of an iron core of the reactor, the cross section S of the iron core of the reactor and the turn number N of a coil of the reactor are used as three variables, and a to-be-solved temperature rise value is obtained by a visualization figure at the premise of meeting the induction quantity and optimizing the volume. The method has the beneficial effects that the length l of the magnetic path of the iron core of the reactor, the cross section S of the iron core of the reactor and the turn number N of the coil of the reactor are used as the three variables, the temperature rise value of the reactor is obtained under the condition of meeting the requirements of the turn number N of the coil and the cross section S of the iron core, and the length l of the magnetic path of the iron core of the reactor, the cross section S of the iron core of the reactor and the turn number N of the coil of the reactor are obtained by utilizing a change tendency chart; the problem of unification is solved by the visualization algorithm, the design process is relatively visual, simple and convenient, and the change of a function is conveniently observed.