The purpose of this study was to investigate the effects of heat moisture treatment (HMT) with different moisture levels on the physicochemical and digestive properties of potato starch(PS) and soybean peptide (SPT) complexes. The morphological characteristics of the complexes were studied by scanning electron microscopy and polarized light microscopy； the thermal properties of the complexes were determined by differential scanning calorimetry； the pasting characteristics of the complexes were determined by Brabender viscometer； the in vitro digestibility of the complexes was determined by Englyst in vitro digestion method. Results showed that PS-SPT complex under HMT showed weaker and fuzzier polarized cross， and more agglomerates. Higher gelatinization temperatures (To， Tp and Tc) and lower enthalpy change (ΔH) were observed for PS-SPT complex under HMT. The higher the moisture level is during HMT， the higher gelatinization temperatures are. Compared with physical mixed conterpart， the PS-SPT complex under HMT displayed higher pasting temperature， significant lower swelling power (SP)， peak viscosity (PV)， hot paste viscosity and cold paste viscosity. The SP and PV reduced gradually with the increase in moisture content of HMT. Lower rapidly digestible starch and higher resistant starch (RS) contents were found for PS-SPT complex under HMT. Thereinto， the PS-SPT complex with 35% moisture level during HMT displayed the lowest RDS (81.53%±1.22%) and highest RS content (11.76%±0.62%). Therefore， HMT significantly changed the physicochemical and digestive properties of PS-SPT complex. These results could be attributed to restructuring of amylose/amylopectin chains， physical barrier of SPT， and interactions between negatively charged groups in PS and side chain groups in SPT. The study will deepen the understanding of food multicomponent interactions and provide important theoretical guidance for low-GI food development containing slowly digestible starch and resistant starch.