A control method for a milk beverage dispensing system and a beverage machine. The dispensing system includes: a mixing device, including a mixing chamber, the mixing chamber having a steam inlet, a fluid inlet and a discharge outlet; a steam generator, connected to the steam inlet; a hydraulic pump, connected between a milk supply source and the fluid inlet; the control method includes the following steps: receiving a milk beverage preparation signal; when determining that the signal is a beverage mode indicating steam output, controlling a pressure relief pipeline of the steam generator to open for a first preset duration, and controlling the steam generator to heat up during the first preset duration; after the first preset duration, controlling the hydraulic pump to activate, and controlling the steam generator to deliver the steam to the mixing chamber, wherein the steam enters the mixing chamber not later than the milk liquid.