A contactless volume control device with adjustable gain and multi-output is configured as a contactless structure with a magnetic slider and a plurality of magnet sensors. The magnetic field of the magnetic slider is sensed by the plurality of magnet sensors to generate a plurality of sensed signals, which allows an output module to provide a data table to show the position of the magnetic slider and the corresponding output voltage thereof according to the sensed signals. Furthermore, the output module is capable of storing multiple variable data to produce different outputs so as to achieve the objective of gain adjusting. Additionally, a processing unit built in the output module has a plurality of output ends so as to output multiple signals. And the magnetic slider and the plurality of magnet sensors have advantages of simple structure, easy manufacture and low cost.