<p>The composite molecular sieve catalysts with long reaction times were successfully synthesized by introducing Cu²⁺/Mn²⁺ and ZSM-5 into the initial gel. The catalysts were characterized with XRD, SEM and NH₃-TPD, and further investigated through the methanol-to-olefin reactions. The results showed that the addition of Cu²⁺ caused the crystallinity of ZSM-5/SAPO-34 (Z-S) to increase significantly, but with addition of Mn²⁺, the crystallinity gradually decreased. With the increase of the Mn²⁺/Cu²⁺ ratio, the desorption summits of the weak and strong acid sites gradually increased, but the weak acid centres gradually dominated, which is herein thought helped reducing formation of the coke. The designed Cu_0.05-Mn_0.05/Z-S samples showed beneficial catalytic performances with a lifetime of 1500&#xa0;min, a 1.5-fold increase compared with the Cu_0.05/Z-S, while their selectivities remained exceeding 89%.</p> Graphical Abstract <p></p>