The invention relates to the technical field of the resource utilization of livestock and poultry breeding waste, and discloses a continuous hydrothermal carbonization system for livestock and poultryexcrement. The continuous hydrothermal carbonization system comprises a fermentation tank, a high-pressure sludge pump, a heater, a carbonization reactor, a cooler, a storage tank, a sludge pump anda solid-liquid separator, wherein the fermentation tank, the high-pressure sludge pump, the heater, the carbonization reactor, the cooler, the storage tank, the sludge pump and the solid-liquid separator are communicated in sequence; the fermentation tank is also communicated with a first gas collection device through a pipeline; the storage tank is also communicated with a second gas collection device through a pipeline. The invention also discloses a continuous hydrothermal carbonization process for the livestock and poultry excrement. The continuous hydrothermal carbonization process comprises the following steps of fermenting the pretreated livestock and poultry excrement in the anaerobic fermentation tank, then continuously inputting into the heater, the carbonization reactor and cooler through power provided by the high-pressure sludge pump, and separating a temperature-lowered carbonization product through the solid-liquid separator to obtain hydrothermal carbon and carbonized liquid. The system is used for treating the livestock and poultry excrement by adopting a continuous hydrothermal carbonization method to prepare the hydrothermal carbon, meanwhile, is used for obtaining the by-product carbonized liquid, and have the advantages of being convenient to operate, easy to maintain, low in production cost, zero-release in pollutant and low in energy consumption, and thelike.