Ordos basin is rich in tight oil resources and single well production in such reservoirs has been substantially increased by the progress of volume fracturing in recent years. However，early developed by conventional fracturing，the single well production and economic benefit was inferior in An83 block of Changqing oilfield. In order to solve this problem，the reservoir characteristics and development dynamic of An83 block was analyzed，and the idea of volume fracturing was put forward. The net pressure of meeting the demands of complex fracture network system was studied by making use of test data of rock mechanics，in-situ stress and natural fracture. And a chart of dynamic fracture width varying with time and rate was established. The temporary plugging timing，injection rate and temporary blocking agent optimization were also researched. Fracturing technology involves fracture tip temporary plugging，multistage temporary plugging in created fractures，high pump rate，low proppant concentration and large amount of slick water and low viscosity liquid system. The new technologies increases the net fracture pressure and creates a complex network system in the side of the fractures. It also leads to an increase of contact area between fracture networks and matrix and thus enhance the lateral remaining oil producing. The technique has been applied to 100 wells in C7 tight oil reservoir of An83 block，and the average well production was increased by 4-5 times than that before fracturing. Besides，it will effectively improve the block development efficiency.