The development of multifunctional organic nanomaterials is extremely essential for their in vivo cancer theranostic applications. In this study, we report a new BDT-IID based conjugated polymer dots (Pdots) platform that can serve as multifunctional nanoprobes for photoacoustic (PA) imaging-guided photothermal therapy (PTT). The novel BDT-IID Pdots are readily fabricated though nanoreprecipitation and can absorb strongly in the near-infrared region (NIR, 650-700 nm). Furthermore, BDT-IID Pdots possess the stable nanostructure and extremely low biotoxicity. In particular, its photothermal conversion efficiency can be up to 45%. More importantly, our in vivo results exhibit that the BDT-IID Pdots are able to offer concurrently enhanced PA imaging signals and sufficient photothermal effect. Consequently, the BDT-IID Pdots can be exploited as a unique theranostic nanoplatform for PA imaging-guided PTT of tumors, holding great promise for their clinical translational development.