A high-pressure common rail system for a low-speed engine with multiple safety protection functions, comprising: an electronic control unit ECU; an electronic control high-pressure fuel pump, provided with an electronic control proportional valve, wherein the electronic control proportional valve is configured to adjust a proportion of feed of a low-pressure heavy fuel from a fuel tank of the low-speed engine into the electronic control high-pressure fuel pump according to a first instruction from the ECU; a first distribution block connected to the electronic control high-pressure fuel pump via a first high-pressure fuel pipe; a second distribution block connected to the first distribution block via a second high-pressure fuel pipe; a common rail pipe connected to the second distribution block via a third high-pressure fuel pipe, wherein a sensor configured to detect a fuel pressure of the high-pressure heavy fuel in the common rail pipe is mounted onto the common rail pipe, and the sensor is connected to the ECU; a plurality of flow limiting valve components are mounted onto the common rail pipe, and each of the flow limiting valve components is connected to one of electronic control fuel injectors via a corresponding_fourth high-pressure fuel pipe; and each of the flow limiting valve components is configured to be closed when a fuel pressure difference between the corresponding fourth high-pressure fuel pipe and the common rail pipe exceeds a set pressure difference; a pressure limiting valve component is further mounted onto the common rail pipe, and the pressure limiting valve component is configured to be opened when a fuel pressure in the common rail pipe exceeds a first set pressure value, so that the fuel pressure in the common rail pipe is stabilized at a target pressure value; the first distribution block is equipped with a shut-off valve component and a safety valve component, wherein the shut-off valve component is configured to perform a pressure relief process according to a second instruction from the ECU; and the safety valve component is configured to be opened when the shut-off valve component and the pressure limiting valve component malfunction and a fuel pressure in the common rail pipe exceeds a second set pressure value; and circulation valve components are further mounted onto the common rail pipe and the electronic control fuel injectors, and each of the circulation valve components is configured to be opened when the low-speed engine is stopped, so that a circulation loop is formed between a fuel tank of the low-speed engine and the common rail pipe, and between the fuel tank of the low-speed engine and each of the electronic control fuel injectors. an electronic control unit ECU; an electronic control high-pressure fuel pump, provided with an electronic control proportional valve, wherein the electronic control proportional valve is configured to adjust a proportion of feed of a low-pressure heavy fuel from a fuel tank of the low-speed engine into the electronic control high-pressure fuel pump according to a first instruction from the ECU; a first distribution block connected to the electronic control high-pressure fuel pump via a first high-pressure fuel pipe; a second distribution block connected to the first distribution block via a second high-pressure fuel pipe; a common rail pipe connected to the second distribution block via a third high-pressure fuel pipe, wherein a sensor configured to detect a fuel pressure of the high-pressure heavy fuel in the common rail pipe is mounted onto the common rail pipe, and the sensor is connected to the ECU; a plurality of flow limiting valve components are mounted onto the common rail pipe, and each of the flow limiting valve components is connected to one of electronic control fuel injectors via a corresponding_fourth high-pressure fuel pipe; and each of the flow limiting valve components is configured to be closed when a fuel pressure difference between the corresponding fourth high-pressure fuel pipe and the common rail pipe exceeds a set pressure difference; a pressure limiting valve component is further mounted onto the common rail pipe, and the pressure limiting valve component is configured to be opened when a fuel pressure in the common rail pipe exceeds a first set pressure value, so that the fuel pressure in the common rail pipe is stabilized at a target pressure value; the first distribution block is equipped with a shut-off valve component and a safety valve component, wherein the shut-off valve component is configured to perform a pressure relief process according to a second instruction from the ECU; and the safety valve component is configured to be opened when the shut-off valve component and the pressure limiting valve component malfunction and a fuel pressure in the common rail pipe exceeds a second set pressure value; and circulation valve components are further mounted onto the common rail pipe and the electronic control fuel injectors, and each of the circulation valve components is configured to be opened when the low-speed engine is stopped, so that a circulation loop is formed between a fuel tank of the low-speed engine and the common rail pipe, and between the fuel tank of the low-speed engine and each of the electronic control fuel injectors.