By means of the quantum theory and negative eigenvalues of the partial transposition, properties of entanglement evolution in system of two two-level atoms coupled to a light field in the Fock state are investigated in the presence of phase decoherence in the multiphoton Tavis-Cumming Model. The influences of the phase decoherence coefficient, dipole-dipole coupling intensity and number of transitional photons on properties of entanglement evolution between two atoms were discussed. The results show that the phase decoherence doesn’t destroy coherence completely but attenuates oscillated amplitude of the entanglement degree between two entangled atoms. With increasing of the dipole-dipole coupling intensity and number of transitional photons, the two entangled atoms approach the entanglement state in which there is a stable entanglement degree finally. The better coherences between two atoms are, the larger value of entanglement degree between two entangled atoms can be obtained, and state in the two entangled atoms are more stable.