Abstract：Based on GAMIT10.71, we study the influence of high-order ionosphere (HOI) delay on the estimation of tropospheric parameters of B2I, B2a and B3I frequency signals of Beidou navigation satellite system(BDS). The experimental results show that during low levels of solar activity, the maximum influence of HOI delay on the zenith total delay(ZTD), north south gradient(NSgrad) and east west gradient(EWgrad) of B2I is 0.80 mm, 0.60 mm and 0.99 mm respectively. The maximum influence of ZTD, NSgrad and EWgrad of B2a is 3.60 mm, 10.77 mm and 10.74 mm respectively. The maximum impact of ZTD, NSgrad and EWgrad of B3I is 1.60 mm, 3.28 mm and 5.90 mm respectively. During the period of high solar activity, HOI has a greater impact on the estimation of tropospheric parameters. The experimental results further show that the influence of HOI on tropospheric parameter estimation is higher in the daytime than at night, and the influence of HOI in low latitude is higher than that in high latitude.