A medical liquid infusion apparatus includes: a housing provided such that an interior thereof is at least partially open at a first time point and is sealed at a second time point later than the first time point; a needle assembly located in the housing and provided such that at least a portion thereof is discharged to an outside of the housing at a third time point later than the second time point by a user's operation; a reservoir that is sealed in the housing after the second time point, receives a medical liquid, and is fluidly connected to the needle assembly; a driving module that is sealed in the housing after the second time point, interposed between the needle assembly and the reservoir, and generates a driving force for discharging the medical liquid after the third time point; a battery module sealed in the housing after the second time point; and a control module that is sealed in the housing after the second time point, and electrically connected to a transmission module and the battery module after the third time point so as to control the driving module.