Foldable top pedal for herringbone ladder and foldable herringbone ladder

The foldable top pedal comprises a front pedal body and a rear pedal body, and the front pedal body and the rear pedal body are rotatably connected together through a connecting structure so that the front pedal body and the rear pedal body can be unfolded or folded mutually. The connecting structure comprises a son spinning buckle, a first mother spinning buckle and a fastener; the sub-turnbuckle is formed by extending downwards from one side of the front pedal along the width direction of the front pedal; the first female rotary buckle is formed by extending downwards from one side, in the width direction of the rear pedal, of the rear pedal, a first connecting groove is formed in the first female rotary buckle, and the first connecting groove comprises an arc part rotationally connected with the child rotary buckle, a first opening and a second opening, the first opening is formed in the axial end part of the arc part and is used for allowing the sub rotary buckle to axially penetrate into the arc part; th