Single-photon imaging is a technology that detects the spatial and temporal information carried by each photon to reconstruct an object image. Single-photon detectors based on superconducting nanowires have the advantages of high efficiency, low time jitter, and wide response spectrum, which is suitable for single-photon imaging applications. The superconducting nanowire delay-line single-photon imager is a novel single-photon imager. It utilizes the high kinetic inductance of the superconducting nanowires to build an ultraslow microwave transmission line. The arrival time and spatial position of photons can be simultaneously measured by reading the arrival times of the output pulses. This study introduces the design principle, geometry structure, and readout method of this imager. Besides, we introduce a single-photon imaging experiment in presence of strong background noise to demonstrate the performance enhancement using the joint optimization of high-performance imaging devices and reconstruction algorithms.