Water and heat transport is the focus of hydrological research in seasonal frost areas. Considering Sanjiang Plain as the study area, this study explored the influence of land use change on soil water and heat transport and the future trend of surface water and heat transport. The effects of land use change on soil water and heat transport were revealed using observation data from the Sanjiang Mire Wetland Experimental Station of the Chinese Academy of Sciences from the period of May 2016 to May 2017. The analysis found evident changes in the water and heat status of different land use types. During conversion from uplands to paddy fields, the surface soil moisture content increased, evapotranspiration increased by approximately 20%, surface infiltration decreased by about 50%, and surface heat flux increased. In a future climate change scenario, the change trend of soil water and heat condition was roughly consistent with the present situation, and the proportion of evapotranspiration of upland and paddy fields in precipitation decreased to 40% and 55%, respectively. These results can provide a theoretical basis for the rational utilization of land and water resources in Sanjiang Plain.