Abstract：Grounded-wire source transient electromagnetic method is a hot research topic nowadays, and it is also very important to study all-time apparent resistivity of this method. In this paper, the author puts forward a fast and efficient calculation method of all-time apparent resistivity for grounded-wire source transient electromagnetic survey. This method can be used to calculate all-time apparent resistivity of multi-component quickly. The defination for all-time apparent resistivity can be achieved by using the translation scalability features of magnetic field characteristic curve in homogenous half space. The theoretical calculation results show that the apparent resistivity definition method does not require iterative with quicker speed and higher precision. Finally, a comparison was made for the resolution of electrical layer of horizontal magnetic field and vertical magnetic field based all-time apparent resistivity. The results indicate that the all-time apparent resistivity of the definition of two components has the same resolution. The results obtained by the authors establish the foundation for the multi-component interpretation technology of grounded-wire source transient electromagnetic method.