Active cooling by endothermic hydrocarbon fuels (EHFs) is considered as a practical approach to deal with the thermal management problem of hypersonic aircrafts. As a typical component of EHFs, decalin is usually thermally stable while it is apt to coke and has poor combustion performance. n-Hexadecane, a normal alkane with a relatively high H/C ratio, can effectively improve the combustion performance of EHFs, and 1-butanol has remarkable anticoking properties. As a fundamental work for fuel design, decalin, n-hexadecane, and 1-butanol were selected as model compounds to construct a surrogate fuel system, which was used to investigate the effects of composition and condition on its thermophysical properties. Densities (ρ) and viscosities (η) of the ternary system of decalin (1) + n-hexadecane (2) + 1-butanol (3) and corresponding binary systems were measured at temperatures T = (293.15 to 333.15) K and pressure p = 0.1 MPa. The excess molar volumes (V m E ) and the viscosity deviations (Δη) of the mixtures were calculated and fitted to several semi-empirical equations. The tendencies of V m E and Δη with composition and temperature were discussed from intermolecular force and molecular size, respectively.