We developed a linear combination of two Flory's melting point theories, one for stretched and the other for solution polymers, to predict the melting point of stretched solution polymers. The dependences of the melting strains on varying temperatures, polymer volume fractions, and solvent qualities were verified by the onset strains of crystallization in our dynamic Monte Carlo simulations of stretched solution polymers under a constant strain rate. In addition, owing to phase separation before crystallization in a poor solvent, calibration of polymer concentration to the polymer-rich phase appears necessary for the verification. Our results set up a preliminary thermodynamic background for the investigation of the multi component effect on strain-induced crystallization of polymers in rubbers and gels as well as on shear-induced crystallization of polymers in solutions and blends.