A substance feeding device includes: a buffer member, a conveying assembly, a weight meter, and a control assembly. The buffer member is configured to store a substance; one end of the conveying assembly is connected with the buffer member; the conveying assembly has at least two conveying ports; the conveying port is configured to connect with a target device; the weight meter is connected with the buffer member and is configured to detect a weight of the substance in the buffer member; each conveying port is provided with one control assembly; the control assembly is configured to control communication and cutoff of a pipeline between the conveying port and the corresponding target device; the control assembly includes a back pressure valve; and the back pressure valve is disposed on the conveying port and capable of being connected with the target device.