Although many approaches based on template replication were developed and applied in DNA detection, cross-contamination from amplicons is always a vexing problem. Thus, signal amplification is preferable for DNA detection due to its low risk of cross-contamination from amplicons. Here, we proposed a cascade enzymatic signal amplification (termed as CESA) by coupling Afu flap endonuclease with nicking endonuclease, including three steps: invasive signal amplification, flap ligation, and nicking endonuclease signal amplification. Because of the advantages of low risk of contamination, no sequence requirement of target DNA, and the universal reaction conditions for any target detection, CESA has a great potential in clinical diagnosis.