To establish the reconstruction method of incidence laser energy based on measuring the temperature rise at back-surface of detector cell, an analytical expression of temperature distribution is derived in detector cell. In terms of the analytical expression of temperature distribution in detector cell, the characteristic factors are confirmed for incidence laser energy reconstruction. By introducing a calibrated-coefficient, the formulae are obtained for laser energy reconstruction and calibrated-coefficient calculation. The calibrated-coefficient is analyzed by numerical simulation that is depended on detector-cell dimensions, laser characteristics, and circumstance conditions. In virtue of modification of convection-irradiation heat loss and laser reflectivity in reconstructed laser energy, the calibrated-coefficients are seasoned with circumstance conditions and different laser parameters. The precision of laser energy measured with calorimetric array is improved effectively.