The utility model discloses a detection apparatus for different horizontal position in muddy water of in site measurement simultaneously interface are co -altitude dissolved oxygen not, including dissolved oxygen shimmer utmost point host computer, several test probe and detection box, it can place on the muddy water interface to detect the box, the fill water cavity who link up about seting up on the detection box, it is provided with the several respectively to detecting the preceding slot and back slot that the interior level of box is extended to detect box leading flank and trailing flank, detection device still includes the inserted sheet, be provided with the probe groove on the inserted sheet, it is fixed that every test probe can put into the probe groove of corresponding inserted sheet, slot or back were in the slot and make test probe's probe arrange fill water cavity in before the inserted sheet can insert, detection device ability simultaneous measurement muddy water interface is co -altitude and horizontal position dissolved oxygen not, the use is rapid and convenient.