The invention discloses a fracturing fluid mass flow continuous liquid preparation system for hydraulic fracturing and a liquid preparation process of the system. The fracturing fluid mass flow continuous liquid preparation system for hydraulic fracturing comprises a water supply unit, a liquid preparation unit, a liquid chemical additive adding unit and a buffer tank which are sequentially communicated through a pipeline, a power driving system and a control system, and electric signals and data signals; a flow meter is arranged on a connecting pipeline between the liquid preparation unit and the liquid chemical additive adding unit, and the whole system is designed in an integral skid-mounted manner. The liquid preparation method prepares a liquid according to the demand of a fracturing site and limitation on special technological parameters based on the power driving system and the control system, can precisely control the starting sequences, the working times and the output quantities of the systems in a liquid preparation process, and can detect a base liquid preparation effect. The system can automatically prepare the liquid according to the demand at the site and immediately convey the fracturing liquid which satisfies the demand of the fracturing process, and is substantially free of residual liquids.