Alzheimer’s disease (AD) is a typical neurodegenerative disease. β-amyloid (Aβ) plaque is the most prominent pathological biomarker associated with the progression of AD. Conventional Aβ probes, including commercial probe ThT, usually suffer from tedious washing procedures. Herein, novel AIE-active Aβ probes with excellent water solubility, named DE-V1-PYC3 and DE-V1-PYOH, were developed for the detection and image of Aβ without tedious washing procedures. Compared with commercial probe ThT, the AIE-active Aβ probes exhibited better sensitivity and affinity to Aβ aggregates. Moreover, for ThT, the washing procedures are essential to obtain high signal-to-noise ratio (SNR) images of Aβ plaques in AD brain tissue slices. DE-V1-PYC3 and DE-V1-PYOH can label Aβ plaques in AD brain tissue slices with high SNR even without tedious washing procedures.