Abstract: Ma-58H is a horizontal exploratory well in Mazhong stratigraphic and lithologic trap in Malang Depression in Santanghu Basin. It is tight tuff limestone reservoir, characterized by high porosity and low permeability, small throat and high heterogeneity. The length of horizontal section is 804 m. In order to tackle the difficulties in fracturing operation in this well, research was conducted on staged fracturing technique in horizontal wells in tight reservoirs. In line with difficulty in rapid gel breaking for fracturing fluid in low temperature wells and damage to tight reservoir after fracturing, a compound fracturing fluid system of ultra-low density and low damage was developed, and through optimization of fracture numbers, fracture lengths and fracture conductivity, optimization of the relation between proppant density and conductivity and optimization of cluster spacing and hole numbers, the fracturing job was successfully completed in this well using fast drilling of bridge plug and staged multi-cluster perforation and fracturing technology. Total frac fluid used in staged fracturing of Ma-58H Well was 7 755.9 m3, total sand consumption was 566.3 m3 , the maximum displacement was 11.2 m3/min, and the daily oil production after fracturing was 131 m3, opening up a new approach for effective development of Santanghu tight reservoirs in Tuha Oilfield.