Mass flow controller and flow control method therefor

A mass flow controller, with a fluid passage provided in the mass flow controller, and a valve connected between an inlet of the fluid passage and an outlet of the fluid passage, wherein the mass flow controller further comprises a control module, a flow sensor, and a pressure sensor, wherein

• the flow sensor is disposed between the inlet and the valve, and is configured to detect a fluid flow of the fluid passage;
• the pressure sensor is disposed at the outlet, and is configured to detect a fluid pressure of the fluid passage;
• the control module is configured to enter a pressure feedback regulation mode in response to a variation amount of a target flow exceeding a preset threshold, and enter a flow feedback regulation mode after the fluid flow detected by the flow sensor meets a first stabilization condition, wherein
• the control module is configured to, in the pressure feedback regulation mode, regulate an opening degree of the valve according to a difference between the fluid pressure detected by the pressure sensor and a target pressure corresponding to the target flow;
• and
• the control module is configured to, in the flow feedback regulation mode, regulate the opening degree of the valve according to a difference between the fluid flow detected by the flow sensor and the target flow;
• wherein the variation amount of the target flow refers to a difference between a target flow currently received by the control module and a previous target flow.