Total atmospheric transmittance measurement equipment and calibration methods were described. Based on the existing research results, the total atmospheric transmittance collection procedures was developed and improved with Visual C++ 6.0, so that the equipment can automatically collect data. The atmospheric transmittance of stellar spectra with different types were measured using the total atmospheric transmittance measurement equipment, and the measured data were processed and analyzed, and the measurement value for six categories of stellar spectra at the upper bound of atmosphere were obtained. Based on the total atmospheric transmittance multi-objective calibration principle and the completion of calibration measurement for the major stellar spectral types, the equipment is able to carry out the real-time measurement of the total atmospheric transmittance.