North America is rich in tight oil reserves. Successful development of tight oil by drilling horizontal well and staged fracturing technology has reshaped the world’s energy outlook. However, the quick production decline rate and low oil recovery factor bring great challenge to the economic development of tight oil at low oil prices. A cost effective way of enhanced oil recovery is the only way for the sustainable development of tight oil reservoirs. This paper reviewed EOR works in laboratory and field tests in North America, and analysed the findings of test results on recovery enhancement. Indoor core experiments indicated that the oil displacement efficiencies of natural gas and CO2 miscible flooding and huff-puff are above 90%; and oil displacement efficiencies of surfactant imbibition and low salinity water flooding were 30% and 19% respectively. Simulation results indicated that CO2 miscible flooding and huff-puff could increase recovery by 15-20%. However, most of the field test results were not ideal and very different from the laboratory results. EOG Resources Inc. in USA is the only company to claim success in the gas injection tests and is adding pilot test blocks and scaling up the tests. Through the analysis of different pilot tests blocks, it is believed that the conventional oil displacement between wells will lead to channeling, and the technical risks of EOR technology is extremely high. Simultaneous gas injection huffs and puffs in several wells in the same block has the potential to significantly improve the recovery rate, but large-scale applications can be limited by factors such as compressor and gas sources. Inter-fracture injection-production in staged fracturing horizontal wells has the potential for further development. It is a revolutionary technology and is worthy of further research.