Cs2AgPdBr5 is a new type of double perovskite with one-dimensional electronic dimensionality, which is expected to be a promising candidate of photovoltaic materials. Considering that defects usually exist in real materials, in this study, we investigate the intrinsic defect properties of Cs2AgPdBr5 from first principles. First, the phase diagram of Cs2AgPdBr5 is calculated. It turns out that its thermodynamic stable region is small, suggesting that the growth conditions should be carefully controlled to obtain high-quality samples. By systematically investigating the Fermi-level pinning behavior, we find that p-type Cs2AgPdBr5 can be obtained at an Ag-poor condition. At the same time, Pd2+i and Pd1+Ag are the only two deep-level recombination centers at 300 K. Therefore, if possible, the amount of palladium should be relatively small in the synthesis process. Our study provides guidance to obtain high-performance Cs2AgPdBr5 materials for photovoltaic applications.