Poly(1,2-butylene oxide) (PBO) is a highly promising and innovative polyether lubricating oil due to its excellent lubricating properties and unique oil miscibility. However, the development of catalysts with low cost, high stability, and excellent catalytic performance for the synthesis of PBO remains a challenge. In this study, we report a series of highly active heterogeneous catalysts composed of layered Zn–Co double-metal cyanides supported by beta zeolite (L-DMC/Al-Beta) for the synthesis of PBO by ring-opening polymerization (ROP) of 1,2-butylene oxide (BO). The catalyst’s superior performance can be attributed to the high dispersion of L-DMC on the surface of the Al-Beta support, which increases the availability of Zn active sites. The inclusion of Al-Beta provides additional Lewis acid sites, which facilitate the coordination and ring opening of BO, resulting in an improved polymerization rate. Through semibatch polymerization processes, well-controlled PBOs with a narrow polydispersity index (D̵ = 1.08–1.53) and desired molecular weights (Mn = 1400–4500 g mol–1) can be obtained. In particular, PBOs exhibit excellent lubricating properties, with a viscosity index of up to 242, a flash point of up to 238 °C, and a pour point as low as −45 °C. Furthermore, PBOs demonstrate excellent miscibility with mineral lubricating oils and can serve as additives to significantly improve their viscosity index. The combination of low cost, easy preparation, and outstanding catalytic performance makes L-DMC/Al-Beta an extremely promising catalyst for the industrial production of high-performance PBO lubricating oils.