The invention discloses a multifunctional cover for a diesel engine, which is in an integral forming structure. The upper part of the cover is provided with ports which are used for connecting with engine oil filter attachments and engine oil cooling attachments; the inside of the cover is provided with channels, which are communicated with associated ports, according to the medium circulation relation; in the height direction, the channel set composed of all the channels is in a layered arrangement structure; the integral middle lower part of the cover is in a bilateral symmetry structure; the middle lower part of the bilateral symmetry structure is provided with a first installation structure part which is used for installing a gear system and a configured shock absorber; each of the two sides of the first installation structure part is orderly provided with a second structure part, a third structure part and a fourth structure part from bottom to top; the second structure part is used for installing an engine oil pump; the third structure part is used for installing a cooling water pump; and the fourth structure part is used for installing a thermostatic valve corresponding to the cooling water pump. The invention has compact structure and simplifies the installation of attachments on the shell of the diesel engine.