Novel floriated Ag nanoplates showing numerous ultra-small gaps (6-8 nm) on the surfaces were synthesized via a seed-mediated method with the assistance of sodium citrate and etching agent hydrogen peroxide. After inner hotspots were certified by simulation, the floriated Ag nanoplates were employed in surface-enhanced Raman scattering (SERS) detection and exhibit high sensitivity and excellent homogeneity in the analysis of 2-naphthalenethiol. Particularly, a sticker-type SERS substrate was developed by mixed the floriated Ag nanoplates into flexible NaCMC film and applied to in situ survey pesticide residue on the surface of apple.