Abstract: The high power density blanket BFEB was split in zones and cooled with helium cooling panels. The mechanics analysis and optimisation for the basic element channel model of helium cooling panels under helium pressure and temperature field were carried out with the Pro/MECHANICA code. The strength check was carried out with the 4th strength theory-octahedral shear stress strength theory. The cross section of the basic element channel model of helium cooling panel was optimised from the rectangular with thin thickness one （12 mm×9 mm×1 mm） to square outer with circular inner one （9 mm×9 mm×φ7 mm or φ6 mm）. As a result, the maximum static Von Mises stress σ_pm and the maximum strain displacement D_pm of the basic element channel model both decreased in orders of magnitude. It let to that the maximum Von Mises stress σ_cm under the combine action of static helium pressure and steady temperature field decreased to be smaller than \,the allowable stress of HT-9 steel. Since the σ_pm was in two-dimensional tensile state, and the σ_tm was in two-dimensional compression state, the addition of them resulted in counteraction to some extent. Therefore, the basic element channel models with cross section of（9 mm×9 mm×φ7 mm） possessed a smaller σ_cm than that with （9 mm×9 mm×φ6 mm） one. The Von Mises stresses σ_cm of basic element channel models SC24₇（arched type） and SC44₇（meander loop type） of helium cooling panels were calculated to be 95.6 and 134.4 MPa,respectively, being 55.0 % and 77.0% of HT-9 allowable stress.