To meet the need for rapid detection of Alexandrium tamarense in field environments， it is imperative to develop a real-time method with high sensitivity and specificity. In this study， a visual method referred to as recombinase polymerase amplification coupled with lateral flow dipstick （RPA-LFD） was developed for rapid detection. The primers for RPA and the detection probe for LFD were designed to specifically target the internal transcribed spacer of A. tamarense by molecular cloning and multiple alignments of the related sequences. The results showed that the successful amplification for RPA could be achieved at optimal conditions of 42 °C and 15 min， and enough products were visually detected by the naked eye through an LFD after an automatic chromatography for 3 min at room temperature. The research indicated that the RPA-LFD exhibited exceptional specificity for A. tamarense and displayed no cross-reactivity with other common algae. The detection limits were as low as 1 copies/μL for plasmid DNA and 1 cells/L for intact cells， representing a 100-fold increase in sensitivity compared to conventional PCR methods. In conclusion， the developed RPA-LFD assay enables rapid detection of A. tamarense-induced HABs while enhancing invasive species screening efficiency at ports.