德宁之殿内东西两壁及北山墙均绘有唐代画圣吴道子的巨幅彩色壁画。东西两侧壁画各高8米，长18米，北山墙壁画高8米，长27米，壁画总面积504平方米。壁画内容为道教题材，描绘天地、五岳、四渎之神会聚北岳恒山的故事，按顺序北壁为《北岳恒山神出巡图》，东壁为《云行雨施》，西壁为《万国咸宁》，作者依据当时神话传说，发挥高超的艺术才能，把天宫、地祗、山川、河流、人物融为一体，活灵活现地展示在人们的眼前。
壁画色彩艳丽，富丽堂皇，画面中上百人物着色浓淡相宜，轻重得当，加上沥粉、贴金的技法，天然矿石色料的应用，使壁画虽历经沧桑仍光彩照人，不失原来的面目。纵观整个画面，似有风行、雷动、雨施之感，如临其境，似画中人，人中画，“吴带当风”之神韵跃然画面之上。
东壁画内容为《云行雨施》，画的是天宫中众天神正在兴师动众，兴云布雨，普降甘霖的具体情节和人物形象。尤其是画中的“苍莽巨龙”体态蜿蜒，两目晶莹，须发柔媚，四爪苍劲有力，腾云驾雾，形若浮云，颇具动感，极惹人注目。
西墙壁画内容为《万国咸宁》，画的是众天神胜利完成为民降福的任务后偃旗息鼓，鸣金收军，得胜回宫的宏大场面。壁画中“飞天神”为全幅壁画之精华，它相貌狰狞，肌肉粗健，横枪倒戈，腾空飞奔，气势逼人，这就是有名的“曲阳鬼”。很久以来，曲阳民间就流传着“曲阳鬼、赵州水”的说法。相传曲阳的飞天神和当年赵州柏林寺大殿壁画上的水均为唐代吴道子所画，故有是说。
由以上不难看出，北岳庙壁画画面大、人物大、气派大，为国内罕见，是研究我国壁画的宝贵资料，它填补了我国绘画史吴派的空白，在道教神话故事中占有重要的地位，也对我国人物画发展及研究起着非常重要的作用。因此，北岳庙壁画是当今稀世珍品，是绘画艺术的瑰宝，是吴派艺术留给后人的宝贵财富。
德宁之殿东壁壁画《云行雨施》
东壁画《云行雨施》，绘有天神、神祗行云布雨，普降甘霖，为民造福的情景。壁画构图巧妙，布局合理，人物最高达3.3米，采用沥粉、贴金的技法和天然矿石色料的应用，画面中人物着色浓淡相宜，轻重得当。壁画中的“苍莽巨龙”体态蜿蜒，须发柔媚，四爪苍劲有力，腾云驾雾形若浮动，颇具动感。
The Mural of ‘Yunxingyushi’
‘Yunxingyushi’, painted on the east wall, expresses that gods and immortals protect and benefit people through favorable weathers. With the exquisite and balanced composition, this mural has its main character up to 3.3 meters high. Painted using gold powder technique and natural mineral pigments, the characters are in soft colors. The dragon was frescoed with soft tentacles but sharp craws; it bears a living resemblance to treading on the clouds.
德宁之殿西壁壁画《万国咸宁》
西壁画《万国咸宁》，描绘的是众天神完成兴云布雨，为民降福的任务后，偃旗息鼓，得胜回宫的宏大场面。壁画中的“飞天神”为曲阳民间流传的“曲阳鬼”，是全幅壁画中的精华之作，它相貌狰狞，肌肉粗健，横枪倒戈，腾空飞奔，气势逼人。据史料记载，为唐代吴道子所画。
殿内东西两侧壁画高8米，长18米。两壁画共有人物百余人，形神兼备，栩栩如生，形象无一雷同。壁画画幅之大，构图之精，气派之宏伟，堪称河北之最，全国瑰宝。
The Mural of ‘Wanguoxianning’
‘Wanguoxianning’, painted on the west wall, presents the grand scene when gods and immortals went back to the heavens after bringing favorable weathers. The Flying God, also known as Quyang Ghost in folklord, is the most successful part of the mural. It, with ferocious look and crude muscle, waved the spear and soared in the air, full of power and grandeur. It is recorded that the mural was painted by Daozi Wu in the Tang Dynasty. Those two pieces of murals are 8 meters high and 18 meters long. More than hundreds of characters in the two murals, without a similar, convey both physical solidity and expressive fluidity. They are well-known in Hebei Province and beyond for their sizable pictures, exquisite composition and magnificent style.
