The 1-D and 2-D emotion models realized by hardware circuits have been studied. However, 3-D emotional model which is most suitable for human emotion has not been considered. In this article, a bionic circuit of 3-D emotional space model is proposed, which can generate brain-like emotions according to the information of visual, speech, and text. The designed memristor circuits are based on the brain emotion theory of limbic system, including thalamus, sensory cortex, orbitofrontal cortex, cingulate gyrus, amygdala, and other circuit modules. Moreover, the perceptual brain and rational brain in the memristor circuits are also considered. The 3-D model in this article is a PAD emotional space model composed of three dimensions: 1) pleasure (P); 2) arousal (A); and 3) dominance (D). Many emotions can be expressed by using the PAD emotional model. In addition, the PAD emotional model composed of memristor circuits is applied to mood congruity, which considers the relationship between emotion and learning. The PAD emotion designed by memristor circuits may provide a reference for bionic robot to realize human-computer emotional companionship.