Abstract: This paper is to introduce the technique and experience of twice enhancement processing for landsat remote sensing image at the mouth of Huanghe River. The purpose of the test is to make a thorough inquiry of how deep the applied latent capacity of the landsat remote sensing image for geography is. By way of operation on the computer, take the once enhancement as the base to do statistics of equil-interval point for image grey values and noticed on the spot of field to design the twice enhancement plan in the course of processing, the facts of image compensate amplifying and scanning have been tought of. At last a colour picture by digital enhancemented in 1:200000 scale at triangle delta of Huanghe River and a part of zone of Huanghe River have been completed. The picture that was processed by way of twice enhancement is clear, and the information is plentiful the tones are varied, the colour it is bright. In a word, a good effective processing is achieved.And it is satisfactory for applied benefit.This test has made a step of positive significance for extracting infomation of geography and open up the use for Geography from landsat remote sensing image.