In order to effectively improve the bio-oil upgrading efficiency, the non-thermal plasma technology was introduced to conduct the online upgrading of bio-oil based on the HZSM-5 and Ti/HZSM-5 catalysis. The effects of different compound modes, including the plasma synergistic catalysis (PSC) and the plasma enhanced catalysis (PEC), on the refined bio-oil yields, physicochemical properties, compositions and catalyst stability were investigated in detail. The results showed that the production of refined bio-oil was gradually decreased with the introduction of Ti ions and plasma-discharge technology, in which the yield of refined bio-oil obtained from Ti/HZSM-5(PEC) catalysis was only 13.84%, but the distribution of hydrocarbons was obviously improved. In comparison, the total hydrocarbon content in the refined bio-oil obtained from Ti/HZSM-5(PSC) catalysis was slightly lower, but the product ratio with higher ratio of hydrogen to carbon was high as 68.89%, so its physicochemical properties were better and the high heating value was up to 36.52MJ/kg. In the PSC method, the impact of plasma on the surface of catalyst was stronger, which made the coking rate of catalyst relatively low, so the coking content of Ti/HZSM-5 employed in the PSC method was the lowest (integral area of 5.24%) and the catalytic stability was the highest. In general, the PSC method was superior to the PEC method based on the catalytic action of Ti/HZSM-5.