To improve the accumulation and dissipation properties of space charge in oil-paper insulation, we doped nano-TiO2 into insulation paper during its preparing process. We tested and analyzed the accumulation and dissipation characteristics of space charge as well as the internal electric field distribution of the oiled paper, using the pulse electroacoustic method (PEA). The results showed that, there is no negative space charge accumulation near the anode of the nano-TiO2 mixed sample under 10 MV/m and 30 MV/m. It is probably because the addition of nano-TiO2 improves the starting voltage of cathode injection charge, introduces traps and then slows down the movement of electrons. It is concluded that the addition of nano-TiO2 to insulation paper is quite effective in improving the accumulation and dissipation properties of space charge and relieving electric field distortion.