An object position detecting device includes a touch film, a first electrode set, a second electrode set, and a sensing and computing circuit. An object position detecting method includes the following steps. Firstly, an object is provided on the touch film. Then, first equivalent capacitance values of multiple first electrode groups of a first electrode set under the touch film are sensed, wherein each first electrode group includes n adjacent first electrodes that are parallel with and connected with each other. Then, second equivalent capacitance values of multiple second electrode groups of a second electrode set under the touch film are sensed, wherein each second electrode group includes m adjacent second electrodes that are parallel with and connected with each other. According to the first equivalent capacitance values and the second equivalent capacitance values, first position information of the object is calculated.