The containing water body is one of the primary factors to impact the safety in production all the time. The transient electromagnetic method plays an important role on the advanced detection of water disaster in tunnel. Because of the detecting particularity in full space condition of tunnel

the detecting and forecasting results are often affected by the layout way of detection

and it often expresses in serial fields such as the interference factor rejection

depth calculation of resistivity

space judgment for abnormality

and so on. For acquiring more reliable detecting results

the testing arrangement is improved in the article. The detecting section in the direction of centre line is added

and it forms the detection method of four-section ahead of tunnel with the roof section

along tunnel section

and bottom floor section. The judging ability of space for the containing water body ahead of tunnel is enhanced. Through contrasting the results of the convention detecting pattern

the advantage of four-section method for geology body judgment is analyzed because of its combining cross-section and longitudinal section. The detecting practices show that it is reliable to use under 10 ?•m as the criteria of the resistivity to forecast the low resistivity field in the tunnel along the 6 coal seams for the advanced detection by the four-section transient electromagnetic method. It has important instructing value for driving safety of tunnel.