Here, tripolycyanamide (TPA) and 2,5-dihydroxyterephthalic acid (DDTA) were used to synthesize crystalline covalent organic framework (COF_DDTA-TPA) which was employed to detect and remove heavy metal ions (HMIs). COF_DDTA-TPA has abundant N-O-O and N-N-O sites and large specific surface area, which can be used as an excellent adsorbent for HMIs. The detection limits for Zn²⁺, Cd²⁺, Pb²⁺, Cu²⁺, and Hg²⁺were 0.85 nM, 0.096 nM, 0.14 nM, 0.072 nM, and 0.084 nM, respectively. The COF_DDTA-TPA was controllably grown on both melamine foam (MF) and macroporous carbon to remove Cd²⁺, Pb²⁺, Cu²⁺, and Hg²⁺ effectively, which avoided some defects of traditional COFs powder such as random orientation, easy accumulation, and poor reproducibility. The COF_DDTA-TPA/MF was further prepared as a water filter device for the removal of HMIs. In addition, the proposed material can detect and remove HMIs in sewage, soil, and blood serum real samples and showed great potential in environmental remediation.