[en] The line intensities of 0010-0000 transition of the symmetric-top PH₃ molecule at several temperature were calculated by directly calculating the partition functions and regarding the rotationless transition dipole moment squared as a constant. The calculated values of the total internal partition sums (TIPS) are consistent with the data of HITRAN database with -0.075% at 296 K. The calculated line intensities data at 1000 K and 3000 K are also in excellent agreement with the data in HITRAN database, which provide a strong support for the calculations of partition function and line intensity at high temperature. Then we extended the calculation to higher temperature. The line intensities and simulated spectra of υ₃ band of the symmetric-top PH₃ molecule at 4000 and 5000 K were reported. The results are of significance for the studying of the molecular high-temperature spectrum including experimental measurements and theoretical calculation. (authors)