This study investigates the effects of varying needle block degree (blockage area ratio of the primary nozzle throat) and dryness fraction (the ratio of gas mass to mass of two-phase mixture) within the primary and secondary flow on the performance of a two-phase ejector, employing CFD numerical simulations under both fixed and varied conditions. The findings reveal the following: (1) Dryness fraction has a significant impact on the performance of the ejector. ER decreases with the decrease of X1 and increases with the decrease of X2, when X1=1 and X2=0.4, the ejector performance can be improved by 253.3% under the optimal area ratio; (2) A higher primary flow dryness fraction and a lower secondary flow dryness fraction are more favorable for enhancing the ejector's performance; (3) When P1 changes, the ejector is most sensitive to changes in P1, slightly less sensitive to changes in An, and least sensitive to changes in dryness fraction; When P2 changes, the ejector is most sensitive to changes in dryness fraction, slightly less sensitive to changes in P2, and least sensitive to changes in An; (4) When varying P1 and P2, the ejector performance is optimal at X1=1 and X2=0.8 (An); (5) Regardless of changes in AR or operating conditions, the adjustable ejector with the needle can effectively enhance the ejector's performance under certain conditions.