A microneedle biosensor includes a microneedle and a substrate. One end of the microneedle is connected to the substrate, an outer surface of the microneedle is provided with a working electrode and a first electrode, an outer surface of the working electrode is provided with an enzyme, and an outer surface of the microneedle biosensor is covered with a biocompatible film. A method for manufacturing a microneedle biosensor includes: manufacturing the substrate and the microneedle in an additive mode simultaneously; spray-printing and curing the working electrode and the first electrode on the outer surface of the microneedle; spray-printing and drying the enzyme on the outer surface of the working electrode; and using biocompatible liquid for spray-printing, and drying the biocompatible liquid to form the biocompatible film. The substrate, the microneedle, the working electrode, the first electrode, the enzyme and the biocompatible film are all manufactured through a full printing method.