The copper thiocyanate (CuSCN) is an inorganic hole transport material with wide-bandgap low cost, high carrier mobility, good stability and excellent light transmittance which has great potential for hole transport layer. However, the current power conversion efficiency (PCE) of the n-i-p type perovskite solar cell (PSCs) based on CuSCN is much lower than that based on spiro-OMeTAD. The main reason is that the PSCs with low open-circuit voltage. It is found that the band gap of the perovskite absorber layer has a great impact on open-circuit voltage of PSCs. PSCs with different band gap 1.55 eV, 1.60 eV and 1.65 eV were fabricated, the PCE of devices based on CuSCN are 12.8%, 14.4% and 10.7%, respectively (The PCE of devices based on Spiro are 20.8%, 19.1% and 17.5%, respectively). The PSCs with a band gap of 1.60 eV form a better energy level alignment with CuSCN and the device with open-circuit voltage of 1.06 V can be achieved. The PCE of champion device is 14.4%. What’s more, when PSCs are exposed to the air with a relative humidity (RH) of 30% to 40%, the unencapsulated PSCs based on CuSCN maintains 92.4% of its initial power conversion efficiency (PCE) at 120 ℃ for 1 h. In a contrast, the device based on spiro-OMeTAD only matains 49.7% of its initial efficiency. It demonstrated that PSCs based on CuSCN with good thermal stability in n-i-p structure devices, which is an ideal hole transport material for stable devices.