This paper presents a design of command queuing engine in eMMC5.1 host system. With the proposed engine, multiple commands can be collected and executed in order of priority instead of executed as they arrive. The proposed engine helps reducing latency on small data transfers so that performance in multitasking scenarios is improved. This design is verified by simulation for various requests and the synthesis results show that it can work at the frequency up to 424 MHz based on 0.13μm CMOS technology.