A miniature portable multifunctional infusion device includes a liquid bottle (4) and a film box body (16) secured to a support frame (1). The film box body (16) is respectively provided with a directional input interface (17) and a directional output interface (14) in communication with the liquid bottle (4) and a needle via an infusion pipe. The film box body (16) is installed with an elastic film (27), and a transmission system (31) is arranged at a side of the elastic film (27). The transmission system (31) includes a miniature direct current motor (32) connected to a frequency modulating system (28). The miniature direct current motor (32) is connected to a spiral straightening device (34) via a speed reducer (33), and the spiral straightening device (34) is connected to a reciprocating film propping device (36) via a two-order shaft (43). A truncated cone (39) of the reciprocating film propping device (36) at a front end is in contact with the elastic film (27). In the infusion device, the miniature direct current motor (32) drives the transmission system (31) to enable movement of the reciprocating film propping device (36), thereby realizing conversion from electrical energy to mechanical energy, and realizing regulation of an infusion speed through a change in the volume the reciprocating film propping device (36) by compressing the film box body (16).