The invention discloses a geothermal system thermal wave arrival degree numerical simulation evaluation method, which comprises the following steps: firstly, establishing a series of geothermal storage layer standard models for representing geothermal storage layers, and forming a standard model set by all the geothermal storage layer standard models; then,solving the standard model set to obtaina dimensionless outlet temperature and an overall thermal recovery ratio; wherein the values of the non-secondary outlet temperature and the overall heat recovery rate are changed along with the change of time, the overall heat recovery rate corresponding to the heat exchange time when the non-secondary outlet temperature is 0.5 is defined as a high-temperature production heat sweep coefficient ET, and the larger the ET is, the higher the heat sweep degree of the geothermal system is. The method is simple in operation and can quantitatively represent the thermal wave arrival degrees of the geothermal system with different crack distributions.