在目标回波光子仍为纯态的假设前提下，推导了M&M′态的量子照明目标探测错误概率边界，并与非纠缠Fock态、NOON态进行了对比.仿真结果表明：M&M′态相对于非纠缠Fock态的探测优势仅受限于信号与闲置光路间光子数的分配比例；这使得以M&M′态作为光源的量子照明探测，能够在更大信噪比动态范围内(至少两倍于NOON态)获得优于非纠缠Fock态的目标探测性能.

NOON states and M&M′ states are both typical path-entangled Fock state. M&M′ state is a new class of path-entangled photon Fock states which possesses photons in both path, and has been confirmed with a good performance in loss environment. In this paper, the detecting error-probability bound of quantum illumination based on M&M′ state was derived under the assumption that the target echo photons are pure states， which was also compared with the error-bounds of Fock state and NOON state. The simulation results show that the error bounds of M&M′ states are no longer limited by the total photon number, but influenced by the proportion of photon number between the signal path and the unused path. Therefore, the quantum illumination system with M&M′ states can offer an enhanced performance over Fock state in a larger dynamic range of signal to noise ratio(at least double time of NOON states).