The problem of laser radiation intensity reconstruction from the temperature along heated target surface is solved. The use of sectioned target allows one to reduce the multidimentional inverse problem on heat conductivity to the set of one-dimentional ones. For different boundary conditions of heating one-dimentional elements there were derived formulas for temperature inversion, which allow one to restore the heat flow at arbitrary thermophysical parameters. The efficiency of restoration algorithms thus constructed, is investigated in numerical experiments.