Explosive mode coupling of low frequency interchange instability in partially ionized plasmas is studied. The coupled equations describing coherent wave-wave interactions of the interchange mode are derived. The possibilities of explosive instabilities for the interchange mode are found. It is shown that there exist the explosive coupling of positive energy wave and negative energy wave, positive energy wave and negative dissipation, and negative energy wave and positive dissipation, in the partially ionized plasmas. The theoretical results obtained can be applied to the ionospheric plasma and the mirror-confined plasma.