The controlled filed test is an essential part of evaluation methods to verify the safety, intelligence and comfort of automated vehicles. Due to the complex, dynamic and large masses of real-world traffic situations, it is very important to generate critical test scenarios with a limited number and a wide coverage, which could evaluate the function features and performance of automated vehicles at different intelligent levels. In this paper, we propose a method to form the basic driving condition group based on function features of level 2 and level 3 automated vehicles, through the permutation and combination of all possible relative position and movement relationships between ego-vehicle and surrounding vehicles in accordance with different traffic conditions and weather types. Based upon the analysis of driving decision for ego-vehicle and adjacent vehicles at each basic driving condition, the crash risk of every possible scenario is estimated to screen out the partly risk-free and much riskier pre-crash situations, leaving the normal driving condition and lower risk pre-crash situations to be the feasible test conditions. Those selected situations can be developed as the preliminary test scenarios by defining the specific test parameters such as vehicle driving parameters and relative movement relationship in controlled filed test, according to some reference including the driver's behavior characteristics, traffic rules, typical driving parameters such as speed, acceleration and deceleration in urban, suburban and highway, vehicle crash database from China and abroad, simulations and so on. Besides, aiming at controlled filed test of Level 2 and Level 3 automated vehicles, a set of evaluation indicators from aspects of safety, intelligence, comfort and efficiency is discussed in this paper.