The decay widths of four-body double-pion decays d* -> pn pi(0)pi(0), d* -> pn pi(+)pi(-), and isoscalar parts of d* -> pp pi(0)pi(-) and d* -> nn pi(+)pi(0) are explicitly calculated with the help of the d* wave function obtained in a chiral SU( 3) quark model calculation. The effect of the dynamical structure on d*'s width is analyzed both in the single Delta Delta channel and the Delta Delta + CC coupled-channel approximations. It is found that in the latter case, the obtained partial decay widths of d* -> pn pi(0)pi(0), d* -> pn pi(+)pi(-), and those of d* to the isoscalar parts of pp pi(0)pi(-) and nn pi(+)pi(0) are about 9.6 MeV, 20.6 MeV, 3.5 MeV and 3.5 MeV, respectively. As a consequence, the total width is about 71.9 MeV. These widths are consistent with our previous estimation by using cross section data and observed width. Apparently, the resultant mass and width in the Delta Delta + CC coupled-channel calculation again support our assertion that the d* resonance is a six-quark dominated exotic state.