Two-dimontional the finite-difference time-domain method was adopted to theoretically study the anomalous optical transmission properties of an asymmetric two integrated metallic nanoslits with an ultrathin separation thickness. The influence of the slit length, the slit number and the incident angle on the optical transmission of the proposed structure were also investigated. The results domenstrate that surface plsamon polaritons, propagating inside the two slits, produce a cross-talk coupling effect via penetrating into the metallic separation, and hybridize into symmetric and antisymmetric modes, resluting in two resonant peaks and a nearly-zero dip in the transmission spectrum; the essential physics of the plasmonic cross-talk coupling for the two integrated slits is the interference between the transverse electric fields of surface plsamon polaritons within the seperation material, and the original phase difference of transverse electric fields between the two integrated slits determines the type of the surface plasmon polariton hybird modes inside it. Since the transmission extremums are associated with the Fabry-Perot resonance inside each slit cavity of the two integrated nanoslits structure, the slit length determines the wavelengths of the tranmission peaks and dip, while the slit number and the incident angle of plane wave only influence the effciency of the tranmission peaks. The two integrated nanoslits structure posses the functions of optical filtering and spatial color dispersion, which have implications on the field of new functional nanooptic devices.