Deep wells of Tarim Oilfield are typical ultradeep and ultrahigh pressure ones， with more than6000mdeep， which is a challenge in application research of staged hydrojet acid fracturing without pulling string. In order to reach a reasonable jet velocity in ultradeep well， the number of muzzles and their radius are optimized. In view of techonical difficulties in Halahatang area and through analysis and optimization， found is a design method， which can not only obtain rapid jet velocity， but also complete field construction in the conditions allowed by pump pressure. The results obtained from field operation in 13 layers of 3 wells show that application of staged hydrojet acid fracturing without pulling string is successful in these ultradeep wells. The effect of fracturing treatment is proven to be good through acid fracturing curve， pump shutdown pressure analysis， comparative analysis on the adjacent wells and flow test， which has an important guiding significance for design and construction of staged hydrojet acid fracturing without pulling string in ultradeep wells.