Biocompatible polymers with non-traditional intrinsic luminescence possess the advantages of environmental friendliness and facile structural regulation, however, it is challenging to regulate the emission property. In this work, five kinds of hyperbranched polysiloxanes (HBPSi) with different alkane chain lengths are synthesized. Optical investigation shows that the emission wavelength of HBPSi is closely related to the alkane chain lengths, namely, short alkane chains will generate relative long-wavelength emission. Electronic communication among functional groups is responsible for the emission. HBPSi molecules aggregate together due to the strong hydrogen bond and amphiphilicity, the functional groups in the aggregate are so close that their electron clouds are overlapped and generate spatial electronic delocalizations. HBPSi with shorter alkane chains will generate larger electronic delocalizations and emit longer-wavelength emissions. Moreover, these polymers show excellent application in the fabrication of fluorescent films and chemical sensing. This work could provide a strategy for regulating the emission wavelength of unconventional fluorescent polymers.