The invention discloses a multi-parameter water quality detection and rating system and a water quality rating method thereof. The system includes a data analysis module and several data acquisition modules; the data acquisition module includes an acquisition control unit, a solution temperature measurement unit, a solution pH measurement unit, a solution The turbidity measurement unit, the solution conductivity measurement unit, the power supply unit and the first communication unit; the data analysis module includes a data analysis control unit, a second communication unit, a display unit and a storage unit; the acquisition control unit is used to collect the collected solution temperature , pH, turbidity, and conductivity are sent to the second communication unit through the first communication unit; the data analysis unit is used to store the solution temperature, pH, turbidity, and conductivity received by the second communication unit into the storage unit for analysis. The water quality level of the solution, and the display unit is controlled to display the solution temperature, pH, turbidity, conductivity and water quality level. The invention has low cost, multiple parameters and high cost performance.