Quantum-illumination-inspired single-pixel imaging (QII-SPI) or computational ghost imaging protocol is proposed to improve image quality in the presence of strong background and stray light. According to the reversibility of the optical path, a digital micro-mirror device acts as a structured light modulator and a spatial light filter simultaneously, which can effectively eliminate 50% of stray light. Accompanied by a 6 dB gain of detection signal-to-noise ratio under an equivalent loss condition, our scheme only requires a simple and minor modification on the placement of the single-pixel detector based on the original SPI system. Since QII-SPI will obtain almost the same reconstruction results as the passive SPI technology in principle, one can, therefore, adjust the placement position of the detector, without exchanging the relative position of the detector and the light source to realize the flexible conversion of the SPI system from active to passive. Also, this work initially discusses the influence of relative coherence time on Hadamard-based SPI driven by a thermal source. This work brings new insights into the optical path design of the SPI technology, paving the way for the practical application of active SPI in stray light environments.