The invention relates to a mechanism for agricultural machinery, in particular to a row space self-adapting header for a stalk and spike reaping corn combine. The header is characterized in that: an upper surface and a lower surface of a harvesting unit is connected with one end of an upper rotating shaft support frame and a lower rotating shaft support frame through bearings respectively. The other end of the upper rotating shaft support frame (18) and the other end of the lower rotating shaft support frame are fixed on a machine frame (20) of the combine. The header can automatically adjust the distance between centers of stalk and spike inlets of two adjacent reaping units so as to adapt to various kinks of planting row space of corn. The header is capable of combining functional blocks according to requirements to meet different requirements on cutting width and power and combine and assemble quickly and conveniently. The header can crush stalks and spikes to make silage which is favorable food for draught animals or to return the stalks and spikes to field. The header has advantages of reasonable and compact structure, light weight, high economic returns, high efficiency and energy conservation.