The invention discloses a method for reconstructing a three-dimensional temperature field positioned on a blast furnace wall and a computer monitoring system. The method comprises the following steps of: acquiring the temperature of temperature measuring points positioned on the furnace walls of a blast furnace bottom section, a furnace hearth section and a furnace bosh section; carrying out pretreatment, namely data cleaning and data complementation, on acquired temperature data; constructing temperature distribution models on two planes, namely an inner side refractory brick center and an outer side cooling wall center, of the furnace wall by adopting periodic cubic spline interpolation on the cross section of the furnace wall and adopting natural cubic spline interpolation in the axial direction of the furnace wall from bottom to top by utilizing the pretreated temperature data; finally constructing the three-dimensional temperature field distribution model of the integral blast furnace wall between the two planes, namely the inner side refractory brick center and the outer side cooling wall center, by adopting linear interpolation, and displaying the temperature distribution state of the blast furnace wall in real time by adopting OpenGL (Open Graphics Library). The method disclosed by the invention effectively solves the problems of abnormal temperature measuring point data, mutually isolated temperature measuring point data and nonvisual integral temperature distribution of the temperature monitoring of the blast furnace wall.