This study was aimed at exploring the value of iterative reconstruction (IR) algorithm to treat the periodontitis using computed tomography (CT) image and analyze the relationship between periodontitis and hypertension. 95 patients with periodontitis were selected, including 43 patients with periodontitis, 41 patients with advanced periodontitis and hypertension, and 11 patients with periodontitis and nonhigh blood pressure (NBP). The IR algorithm was introduced to the CT image scanning of them to reduce the noise. In addition, the CT value was statistically analyzed. High-sensitivity C-reactive protein (hs-CRP) and interleukin 6 (IL-6) were dramatically increased compared with periodontitis patients with NBP and with hypertension ( P < 0.05 ). After the IR algorithm of the image, the quality, information, and mean square error (MSE) of the image were all effectively improved. Image with a 50% dose showed the lowest noise, but the reconstruction algorithm improved the low-contrast resolution. Moderate and severe periodontitis was independently related to hypertension. Inflammatory cytokines were independently related to hypertension of periodontitis patients ( P < 0.05 ). Therefore, it was concluded that the IR algorithm could effectively improve the spatial resolution of the CT image when it was adopted to treat periodontitis and showed a high accuracy rate; the incidence of hypertension in patients with periodontitis was relatively high, and it had a certain relationship with periodontitis; and inflammatory cytokines were related to periodontitis and hypertension of patients.