The utility model relates to the technical field of industrial sewing machine manufacture and particularly relates to a servo electric control analog quantity input circuit which is mainly formed by a photoelectric coupler, an analog quantity input end and a main controller. The circuit is mainly used for the analog quantity input of thermally electric control, an expensive linear optocoupler is replaced by a common cheap optocoupler, through setting various parameters, the analog quantity input of an analog quantity input end is realized, and the circuit has the advantages of simple structure and low realization cost.