A set of mixed sediments of volcanic ash and carbonate are widespread in the second Member of the Permian Lucaogou Formation (P2l2) in the Tiaohu- Malang sag, Santanghu basin. However, the conditions and main controlling factors of shale oil in the P2l2 remain unclear. So, organic/inorganic geochemical analysis, core conventional analysis (porosity, permeability, and oil saturation), X- ray diffraction (XRD), thin sections, Ar- ion milled field emission scanning electron microscopy (FESEM), high pressure mercury injection (HPMI)- nuclear magnetic resonance (NMR)，and other methods were used in this study. The results showed that: ① The P2l2 developed a set of low- mature and mature source rocks, which were dominated by tuff, with large thickness and high abundance of type Ⅰ kerogen, and an average TOC value of 5%. ② The P2l2 reservoir was characterized by complex lithology and poor physical properties, with porosity ranging from 1. 1% to 9. 5% and the permeability less than 0. 1×10-3μm2. Nanometer scale intergranular pores, intercrystalline pores, and dissolution pores were the main reservoir pore types. Tuff and dolomite have the best pore structure, higher oil saturation, and stronger fluid mobility, followed by tuffaceous dolomite and dolomitic tuff. ③ Advantage lithofacies, favorable source and reservoir combination, and good fault- fracture system control the P2l2 shale oil accumulation, which has the characteristics of “source and reservoir integration, dominant facies belt control the reservoir, as well as fracture and dissolution control the sweet pot”.