The invention relates to a new method for preparing butylene succinate by combining solution with melt phase polycondensation. The method comprises the following steps: S21) weighting 1,4-succinic acid and 1,4-butanediol, adding into a reactor, adding a defined amount of rare earth oxide as a main catalyst and Na-X type molecular sieve as a catalyst promoter and adding a solvent, thereby forming a mixer; S22) quickly increasing temperature of the mixture to 135-145 DEG C under the stirring condition and reacting for 0.5-2h; S23) steaming the solvent in the products obtained in the step S22); S24) under a vacuum condition, quickly increasing the temperature of the products obtained in the step S23) to 200-240 DEG C and stirring and reacting for 1-4h; S25) collecting the reaction products, taking out the reaction products under high temperature and cooling the reaction products to room temperature.