The present invention relates to an automotive tyre non-skid device for snowfields to increase adhesion to pavement covered with ice or snow, in particular to a diagonal bead chain stress reducing pinch plate and a diagonal bead chain. Through configuration of stress reducing pinch plates and stress reducing transition chains disposed on two sides of a second connecting assembly, concentrated stress at the connector roots of steel cables of the stress reducing transition chains are isolated, dispersed and relieved, and the service life of the steel cables are prolonged. At the same time, the present invention has the advantages of simple structure, stable performance, convenient modification and low manufacturing cost.