The invention relates to a portable multifunctional picnic mat, which comprises a mat body, wherein a packing mat is connected to the edge of one side of the mat body; a zipper teeth tape of a zipper is arranged on three edges of outer side of the packing mat; along a connecting line connected to the mat body, the packing mat is reversely folded on the back of the mat body, so that a combined region is formed; another zipper teeth tape of the zipper is arranged on the position, corresponding to the three edges of the outer side of the packing mat, of the combined region; a packing bag is formed when the mat body is positively folded and the two zipper teeth tapes of the zipper are connected; and the folded mat body is arranged in the packing bag. The picnic mat is formed when the mat body is completely unfolded and a storage bag is formed when the mat body is folded; and the multifunctional picnic mat is low in cost and broad in application scope, and the picnic mat can bring about relatively great convenience to people.