In-situ sensor is an important data source of intelligent urban construction, which plays a decisive role in urban resource coordination, disaster early warning, dynamic monitoring analysis and other fields. The present sensor observation access method does not consider the flow characteristics of sensor data with no uniform access model resulting in a failure of unified filtering of time and space under the observation and poor reusability of the sensor access components. In this paper, an in-situ sensor observation access method based on storage and computation separation is proposed. Upon the station-based observation access uniform model, the in-situ sensor access process is divided into three parts:data acquisition, observation filtering and observation storage. The experimental results show that the method can effectively access the heterogeneous in-situ sensor station based on the sensor observation access uniform model and realize the attribute filtering in the specific time and space scenes of the multiple in-situ sensor observation results.