The invention provides a thermistor temperature detecting method based on DSP, wherein a relational expression between T and lgR-T is obtained by utilizing the temperature of thermistor R-T characteristic detection power equipment and fitting a lgR-T curve in DSP. The method comprises the following steps of: converting the computation for lnR into the approximate operation of addition, subtraction, multiplication and division, obtaining a computing formula by adopting a high-item truncation approximate computing method, then determining a segmenting mode by adopting an error comparison method, and finally obtaining the lnR value of each segment by adopting a segmentation algorithm to realize accurate temperature computation. The temperature detecting precision is greatly improved by adopting the method; the method is simple to realize and has high operational speed; the hardware structure is simple, and the cost is saved.