In order to improve the solubility and defoaming/foam inhibition ability of silicone antifoam agents in water, a series of hydrogen-containing polysiloxanes (LPMHS) with different chain lengths (m+n) and ratios of siloxane links to hydrogen-containing siloxane links (m/n) were prepared by polycondensation under acidic condition, using octamethylcyclotetrasiloxane (D4) and tetramethylcyclotetrasiloxane (D4H) as condensate monomers, and hexamethyldisiloxane (MM) as a terminating agent. A series of butynediol ether modified organosilicone (PSi-EO) surfactants with anti-foaming effect were prepared by grafting butynediol diethoxylate (BEO) molecules on the LPMHS chain, and then hydrogenated with BEO. The structures of PSi-EO were characterized by FTIR and 1HNMR, and the defoaming performance, surface activity and wetting and spreading properties of PSi-EO were tested by bulging, water contact angle and dynamic light scattering to investigate the conformational relationship between structure and performance. The results showed that when m/n=4, the defoaming ability of PSi-EO continued to decrease with the increase of m+n (4+1~24+6), and the foam inhibition ability was highest at m+n=16+4 (foam inhibition time of 16.53 min), but after that there was a tendency to decrease, whereas the critical micelle concentration (CMC) of its aqueous solution continued to decrease, the minimum surface tension continued to increase. The minimum surface tension of PSi-EO aqueous solution was determined by the siloxane chain length (m+n). When m+n=20, with the decrease of m/n (18/2~14/6), the defoaming ability of PSi-EO increases and the foam inhibition ability decreases, and the PSi-EO with m/n=17/3 has an excellent defoaming and foam inhibition ability (defoaming time of 71.28 s; foam inhibition time of 19.34 min). With the increase of m+n and the decrease of m/n, the molecular chain of PSi-EO was extended and the amount of hydrophilic group grafting was increased, and its contact angle was also increased, and the wetting ability was reduced. PSi-EO can form spherical micelles in aqueous solution, and the smaller aggregates can self-assemble to form large and complex aggregates with an average particle size of 100~300 nm, and its aggregate morphology is independent of its siloxane chain length and chain-length ratio. The absolute values of the standard adsorption free energies (ΔG0 ads) of PSi-EO were higher than those of the standard micellar free energies (ΔG0 mic), indicating that PSi-EO molecules were more inclined to adsorb at the gas-liquid interface, and thus the surface tension of the vesicle film in the vicinity of the molecules can be rapidly reduced, which can lead to the bubble bursting.