Abstract: As for the comparison of investment and cost in the seismic exploration of the current oil department, the use of the cost unit like kilometer and square kilometer cannot reflect the unit length or how many data points the unit area has or how many times each point receives the data, namely unable to reflect the engineering workload of seismic exploration. The data points and the times each point receives the data in the seismic exploration are raised as the engineering workload for the seismic project. The cost-calculating unit is “point-time.” This article discusses calculation of unit length and the “point-time” in the unit area, the relations between the point-time and the unit cost variation as well as calculation of the seismic engineering workload in the concrete project.