A health monitoring device having gas detection function is disclosed. The health monitoring device includes a main body. The main body has at least one inlet and at least one outlet, and includes a gas detection module. The gas detection module includes a piezoelectric actuator and at least one sensor. Gas is inhaled into the main body through the inlet by the piezoelectric actuator, is discharged out through the outlet, and is transported to the at least one sensor to be detected so as to obtain gas information.